chore: align the merged site with its checks

The two redesign branches and the archive repair met in the testing guide and the prose rules: list test_archive_recipes, drop three clause semicolons, write the forbidden glyphs as escapes in the image test. README and mkdocs.yml regenerated from the merged generator.

scripts/fetch_site_images.py

@@ -9,7 +9,7 @@ committed, and records where each came from in a ``sources.json`` beside
 them. The site build only reads those copies (``sitediagrams.localize_images``).
 
 Raster images are normalised to a square PNG (96 px for logos, 48 px for
-system icons) so every tile has the same weight; SVG is kept as published.
+system icons) so every tile has the same weight, and SVG is kept as published.
 Normalising needs Pillow. This is a maintenance tool run by hand when a
 logo changes, not a build step: the build stays on the standard library
 and PyYAML.

scripts/sitediagrams.py

@@ -47,7 +47,7 @@ PAD = 10
 WIDE = 720
 NARROW = 340
 
-# Default colours for an SVG read outside the page; the stylesheet replaces
+# Default colours for an SVG read outside the page. The stylesheet replaces
 # them on the site through the rb-d-* classes.
 INK = "#1f2233"
 FILL = "#f5f6fa"
@@ -315,8 +315,8 @@ def _folder(name: str) -> str:
     return str(registry()[name].get("extract_to", "")).strip()
 
 
-# Frontends and emulators shown in the explainer. Each pair is one a user
-# meets together; tests check that the platform runs that emulator.
+# Frontends and emulators shown in the explainer, each pair one a user meets
+# together. Tests check that the platform runs that emulator.
 CHAIN_EXAMPLES = (("batocera", "duckstation"), ("emudeck", "pcsx2"), ("retroarch", "beetle_psx"))