diff --git a/CHANGELOG.md b/CHANGELOG.md
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--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,103 @@
+# v0.5.0.1
+
+## Fixes
+
+- Added doc-files to the .cabal-file. README.md, LICENSE and CHANGELOG.md.
+
+# v0.5.0.0
+
+## Breaking
+
+- `IsAst` class methods `parser`/`toTextBuilder` now take a `Settings` parameter
+  to control parse/render options (e.g. nullability `?` markers). Migration:
+  `parse x` -> `parse mempty x`, `toText x` -> `toText mempty x`,
+  `parseWithPosError x` -> `parseWithPosError mempty x`. New public module
+  `PostgresqlSyntax.Settings` provides the `Settings` type and the
+  `nullabilityMarkers` constructor.
+- Nullability `?` markers in `Typename` are now opt-in via
+  `nullabilityMarkers True`. In standard mode (`mempty`) they are not
+  recognized - both flags parse as `False` and a literal `?` in their
+  position is a parse error. Markers no longer accept a preceding space:
+  `int ?` -> `int?`. Extended mode gives up one spelling of real Postgres:
+  `x::jsonb? 'b'` (unspaced jsonb key-existence operator); use
+  `x::jsonb ? 'b'` or `jsonb_exists(x, 'b')`.
+- Removed `PostgresqlSyntax.Parsing` and `PostgresqlSyntax.Rendering`. Every
+  type's parser and renderer are now the `parser`/`toTextBuilder` methods of
+  its `IsAst` instance (exported from `PostgresqlSyntax`), and the top-level
+  entry points moved to the `PostgresqlSyntax` module: `Parsing.run`/`.runWithPosError`
+  became `PostgresqlSyntax.parse`/`.parseWithPosError`, generalized to work over
+  any `IsAst` type rather than taking an explicit parser argument.
+- `PostgresqlSyntax.KeywordSet` and `PostgresqlSyntax.Validation` are no longer
+  part of the public API surface.
+- Several former type aliases are now distinct ADTs/newtypes instead of bare
+  `Either`/`Maybe`/primitive aliases: `SelectStmt`, `SelectClause`,
+  `ExplicitRow`, and the primitive-wrapper newtypes `Sconst`, `Bconst`,
+  `Xconst`, `Iconst`, `Fconst`, `Op`, `OptVarying`, `Timezone`,
+  `IntervalSecond`, `OptOrdinality`. Code that pattern-matched these as
+  `Either`/`Maybe`/`Text`/`Bool` directly needs to match on the new
+  constructors instead.
+- Removed the `SuffixQualOpAExpr` constructor of `AExpr`. It modelled the
+  postfix operator production (`a_expr qual_Op`), which Postgres removed in
+  version 14 - `x OPERATOR(pg_catalog.+#)` is a syntax error in every
+  supported server version, so the parser no longer accepts it and the
+  renderer can no longer emit it. Code pattern-matching or constructing
+  `SuffixQualOpAExpr` needs to drop those cases. This also removes a family
+  of round-trip failures: the rendering `<operand> <operator>` left the
+  operator without a right-hand side, so reparsing swallowed whatever
+  keyword followed (`PRECEDING`, `FOLLOWING`, `ROWS`, an implicit column
+  alias, or - in the postfix case specifically - the `?` of the `Typename`
+  nullability extension) as its operand. Only the postfix-triggered `?`
+  swallow is fixed by this; `Op "?"` colliding with the nullability
+  extension as a *binary* operator is a separate, still-open issue.
+
+## Fixes
+
+- Fix the `AExpr`/`BExpr` renderers (and related expression renderers) being
+  precedence-naive: operators were concatenated without parenthesization, so a
+  non-canonical but valid AST (e.g. `(NOT x) - y`) could render to SQL that
+  re-parses to a different tree (`NOT (x - y)`). Renderers now parenthesize
+  based on operator precedence, making render -> parse round-trip safe for the
+  full value space of each type, not just parser-canonical trees.
+
+# v0.4.5.0
+
+## Non-breaking
+
+- Derive `Data` for every AST type in `PostgresqlSyntax.Ast` (#6). Enables
+  generic (SYB-style) traversals and transformations over the syntax tree,
+  e.g. for expression normalization.
+- Add `parseWithSourcePosError`, like `parseWithPosError` but pairing each
+  error with a `Text.Megaparsec.SourcePos` instead of a raw `Int` byte
+  offset, so callers (e.g. `hasql-th`, see
+  [nikita-volkov/hasql-th#35](https://github.com/nikita-volkov/hasql-th/issues/35))
+  can report line/column positions without recomputing them from the input.
+
+# v0.4.4.0
+
+## Fixes
+
+- Fix parsing time growing exponentially with the nesting depth of an expression (#8).
+  Inputs as small as `((((((((((((a + b))))))))))))` previously did not finish parsing;
+  they now parse in well under a millisecond. Three grammar alternatives each parsed
+  the content of a parenthesised group before discovering they did not apply, tripling
+  the work per level of nesting; they are now left-factored so each group is parsed once.
+  Parsing time is linear in input size, with a quadratic term in nesting depth alone
+  (1000 characters of pure nesting take about a second; realistic input is unaffected).
+
+## Non-breaking
+
+- Redundant parentheses around a sub-select now parse to a canonical shape.
+  `((select 1))` produces `WithParensSelectWithParens`; the equivalent
+  `NoParensSelectWithParens` of a `SelectNoParens` carrying nothing but that same
+  parenthesised select is no longer produced. The two rendered identically, so this
+  only affects which of two equivalent trees you get back. Trees that carry a
+  set operation, sort clause, limit or locking clause around the parenthesised
+  select are unaffected.
+
+# v0.4.3.2
+
+## Fixes
+
+- Fix keyword error reporting under megaparsec >=9.8 (#20)
+- Fix OFFSET/aExpr round-trip failure for `OPERATOR(...)` prefix (#11, #22)
+- Fix hedgehog generator for `type_function_name` to use its own keyword set
diff --git a/README.md b/README.md
new file mode 100644
--- /dev/null
+++ b/README.md
@@ -0,0 +1,6 @@
+# postgresql-syntax
+
+[![Hackage](https://img.shields.io/hackage/v/postgresql-syntax.svg)](https://hackage.haskell.org/package/postgresql-syntax)
+[![Continuous Haddock](https://img.shields.io/badge/haddock-master-blue)](https://nikita-volkov.github.io/postgresql-syntax/)
+
+Postgres syntax tree and related utils extracted from [the "hasql-th" package](https://github.com/nikita-volkov/hasql-th).
diff --git a/postgresql-syntax.cabal b/postgresql-syntax.cabal
--- a/postgresql-syntax.cabal
+++ b/postgresql-syntax.cabal
@@ -1,6 +1,6 @@
 cabal-version: 3.0
 name: postgresql-syntax
-version: 0.5.0.0
+version: 0.5.0.1
 category: Database, PostgreSQL, Parsing
 synopsis: PostgreSQL AST parsing and rendering
 description:
@@ -13,6 +13,10 @@
 copyright: (c) 2020, Nikita Volkov
 license: MIT
 license-file: LICENSE
+extra-doc-files:
+  CHANGELOG.md
+  LICENSE
+  README.md
 
 source-repository head
   type: git