Add changelog.

List zjot (Zig) implementation.

Use the JavaScript reference implementation, not the Lua one...

Clarify heading ID excludes non-textual elements (symbols, footnotes)

Exclude footnote references from auto-generated heading IDs

Say that .djot and .dj may both be used as extensions.

Add note on MIME type.

Add JetBrains IDEs plugin to tooling section

Add PHP link to language list in index.html

Update README to include WordPress plugin for djot-php (#356)

Add djot-php (PHP) implementation (#353)

clarify inline precedence for verbatims (#345)

Fix djot.el.

docs: add helix support to tooling section and slightly reformat its structure (#335)

Fix whitespace in negative charclasses (#331)