feat: redesign the landing page for 0.36.0

The pages are now generated by build.py from src/template.html, a
language-neutral src/data.json and per-language strings in src/i18n, and
a check workflow fails when a committed page is out of date. The landing
leads with the built-in coding agent, the comparison table runs from what
most editors offer to what only termide does, and the screenshots and
theme previews are re-recorded by the reproducible pipeline in the main
repository. Version bumped to 0.36.0.

Author: nizovtsevnv

.github/workflows/check.yml

@@ -0,0 +1,16 @@
+name: check
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  pages-up-to-date:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+      - name: Generated pages match src/
+        run: python3 build.py --check

.gitignore

@@ -0,0 +1 @@
+.DS_Store