The 20.2.0 section had drifted a long way from how this changelog is written.
Measured against the rest of the file, its entries averaged 890 characters
where 18.3.0 runs about 250, and it opened straight into a bullet list with no
`**Highlights:**` paragraph.

Worse than the length, five of its eleven `Fixed` entries did not belong there
at all:

  - two duplicated their own `Performance` entries, describing the same change
    twice
  - three documented bugs that never reached a release — one said outright
    that no released version was affected, another was latent until a
    same-cycle change exposed it, and the third was about the test suite

A user reading those learns nothing; they record how the work went, not what
changed for them.

CONTRIBUTING.md now states the convention: `Subsystem: what changed` in one or
two sentences, the mechanism and the symptom without the discovery narrative,
nothing that only ever existed inside an unreleased cycle, `Changed` reserved
for user-facing API changes, and measurements quoted no more precisely than
they were taken.

20.2.0 is rewritten to match: 11 entries averaging 393 characters, a Highlights
opener, and issue references in the bare `(#1234)` form the older sections use.

Released sections are left alone. They are published — each has a GitHub
release carrying a copy — so editing them here would only make the two
diverge.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012Aa37KGXZcnVrbn1yG4j1N

Entries across the 19.3 to 20.1 range had drifted well past the house style,
peaking at 20.1.0's three entries averaging 1166 characters. Trimmed to the
one or two sentences CONTRIBUTING now describes, keeping the mechanism and the
symptom and dropping the discovery narrative.

    version     entries   before   after
    20.1.1            7      538     277
    20.1.0            3     1166     458
    20.0.0           51      423     352
    19.8.0           26      525     354
    19.7.1            3      539     244
    19.7.0           39      525     274
    19.5.0           51      636     382
    19.4.0           12      511     268
    19.3.0           21      647     305

19.4.0, 20.1.0 and 20.1.1 were rewritten by hand, since they also needed
restructuring into `Subsystem: what changed`. The rest already had that shape
and only needed shortening.

No entry was removed and no fact dropped beyond the narrative — these are
published notes, so the record stays intact. Verified afterwards: nothing cut
mid-clause, and one entry that split at "(e.g." was repaired by hand.

Note the published GitHub releases still carry the original text, so the two
now differ.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012Aa37KGXZcnVrbn1yG4j1N

…eference space

The feature list named seven blend modes. There are thirteen, and as of 20.2
every one of them works identically on WebGPU, WebGL 2 and Canvas — `exclusion`
landed in 20.0 and the six shader-path modes in 20.2. Understating that in the
README hides the release's headline.

Also mentions the particle reference space, since "blend modes" was the only
particle capability called out and this is the larger addition.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012Aa37KGXZcnVrbn1yG4j1N

DOC_README.md is what `pnpm doc` passes to typedoc as `--readme`, so it is the
landing page a new user reads first. It had gone unmaintained across eight
releases:

  - the Quick Start had no `await app.init()`, mandatory since 20.0, so the
    very first snippet anyone copied could not run
  - the feature table said "WebGL & Canvas 2D" through the whole of 20.x,
    omitting the backend that release was built around
  - the shader sample taught `renderable.shader =`, deprecated since 19.2.0 in
    favour of `addPostEffect()`

The cause is structural: two READMEs with overlapping content in different
directories. The root one is updated every release; this one, tucked inside
packages/melonjs, was invisible. It now sits beside the README it duplicates.

Placement alone does not enforce anything, so `scripts/check-doc-readme.ts`
runs before typedoc and fails the build when a sample constructs an
`Application` without awaiting `init()`, when a sample uses a member marked
`@deprecated` anywhere in src, or when the page stops naming a renderer the
engine supports. Deprecated members are scanned from the source rather than
listed, so something deprecated later is covered without anyone remembering
this file. Both original bugs were verified to fail it.

Also fixes the ParticleEmitter class doc, which rendered as a broken category
name in the sidebar — "Particles ### Blend modes An emitter draws no pixels of
its own..." — because `@category` is a block tag and the sections added in
#1604 and #1606 sat after it, so they were absorbed into its value. Prose now
comes first with `@category` last, and the two `@example` tags are fenced code
blocks, which cannot swallow what follows. Verified in the built output: both
sections render as h3 headings and no raw markdown leaks.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012Aa37KGXZcnVrbn1yG4j1N

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012Aa37KGXZcnVrbn1yG4j1N