fix(docs): escape MDX special characters in changelog and linux guide (#4849)

- Wrap `<=8` in backticks in changelog.mdx to prevent MDX interpreting
  `<` as JSX element start
- Remove unsupported {#custom-id} syntax from heading in linux.mdx as
  Starlight/Astro auto-generates heading IDs

This fixes the docs build failure in the Deploy to GitHub Pages workflow.

docs/src/content/docs/changelog.mdx

@@ -35,7 +35,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## Changed
 - Switch to goccy/go-json for all runtime JSON processing (method bindings, events, webview requests, notifications, kvstore), improving performance by 21-63% and reducing memory allocations by 40-60%
 - Optimize BoundMethod struct layout and cache isVariadic flag to reduce per-call overhead
-- Use stack-allocated argument buffer for methods with <=8 arguments to avoid heap allocations
+- Use stack-allocated argument buffer for methods with `<=8` arguments to avoid heap allocations
 - Optimize result collection in method calls to avoid slice allocation for single return values
 - Use sync.Map for MIME type cache to improve concurrent performance
 - Use buffer pool for HTTP transport request body reading

docs/src/content/docs/guides/build/linux.mdx

@@ -146,7 +146,7 @@ sudo pacman -S base-devel
 
 Alternatively, run `wails3 task setup:docker` and the build system will use Docker automatically.
 
-### AppImage strip compatibility {#appimage-strip-compatibility}
+### AppImage strip compatibility
 
 On modern Linux distributions (Arch Linux, Fedora 39+, Ubuntu 24.04+), system libraries are compiled with `.relr.dyn` ELF sections for more efficient relocations. The `linuxdeploy` tool used to create AppImages bundles an older `strip` binary that cannot process these modern sections.