chore: move coding guidelines from .github to docs/ (#358)

* Reorganized repository documentation and updated internal configuration to reference the new docs location.
Documentation
* Updated contributor and instruction guides to point to the relocated documentation files so links and references remain correct.
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Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: softhack007 <91616163+softhack007@users.noreply.github.com>

docs/web.instructions.md

@@ -0,0 +1,29 @@
+---
+applyTo: "wled00/data/**"
+---
+# Web UI Coding Conventions
+
+## Formatting
+
+- Indent **HTML and JavaScript** with **tabs**
+- Indent **CSS** with **tabs** or **spaces**
+
+## JavaScript Style
+
+- **camelCase** for functions and variables: `gId()`, `selectedFx`, `currentPreset`
+- Abbreviated helpers are common: `d` for `document`, `gId()` for `getElementById()`
+- Mark WLED-MM additions with `// WLEDMM` comments
+
+## Key Files
+
+- `index.htm` — main interface
+- `index.js` — functions that manage / update the main interface
+- peek.js, liveview*.htm - live preview in main interface
+- `settings*.htm` — configuration pages
+- `*.css` — stylesheets (inlined during build)
+
+## Build Integration
+
+Files in this directory are processed by `tools/cdata.js` into generated headers
+(`wled00/html_*.h`, `wled00/js_*.h`).
+Run `npm run build` after any change. **Never edit generated headers directly.**