docs: add Remotion quickstart guide

README.md

@@ -1,24 +1,50 @@
 # Video-related files for NCMR songs
 
-This repo houses the video-related, code-like files for NCMR music videos. 
+This repo houses the code-like files for NCMR music videos. Binary assets live elsewhere.
+
+## Structure
+
+### `master` branch — shared template
+
+This branch holds the common scaffolding:
+
+- **Remotion project** — entry point, root component, and a placeholder composition
+- **`ffmpeg.sh`** — helper for baking ASS subtitles or bypassing with static image + audio
+- **`src/lrc2srt.ts`** — legacy LRC → SRT subtitle converter
+- **Build config** — TypeScript, ESLint, Prettier, Remotion studio
+
+### Song branches
+
+For each song, create a branch `<song-name>/master` (and optionally feature branches
+like `<song-name>/synced-lyrics-remotion`):
+
+```
+git checkout -b <song-name>/master
+```
+
+Copy the shared template into the song branch, then add song-specific files:
+
+```
+mkdir -p <song-name>
+# Place your song-specific compositions, assets manifests, etc.
+```
+
+The `master` branch remains protected and mostly immutable. Song branches are independent.
 
 ## Guideline
 
-### gitignored (not tracked here)
-- binary input assets (audio, image, fonts, material video clips if any)
-- video output
+### Git-ignored (not tracked here)
 
-For untracked input assets, a bill of materials listing everything and explaining what each is will be mandatory.  
+- Binary input assets (audio, images, fonts, material video clips)
+- Video output (`out/`, rendered files)
 
-### branching rule
+For untracked input assets, a **bill of materials** listing everything and explaining
+what each file is will be mandatory. Keep it as `BOM.md` alongside your song assets.
 
-This repo has specialised local branching rules and will supersede any generic git operation conventions.
+### Branching
 
-- `master` serves as the minimal template and remain protected and mostly immutable
-  - [Remotion](https://www.remotion.dev/) project scaffolding
-  - `ffmpeg` helper script for baking in `ass` styled subtitles or bypassing the Remotion route (static image + audio)
-  - legacy lrc->srt conversion script
+- `master` — minimal template, protected
+- `<song>/master` — song-specific work
+- `<song>/<feature>` — parallel features for a song
 
-- for each song, a song root named `<song-name>/master` should be created, for the very least
-  - usually, working on a song root incrementally is the norm and totally acceptable
-  - branches for parallel features (e.g. `<song-name>/synced-lyrics-remotion`, `<song-name>/overlay-ass`) may be created.
+This repo's branching rules supersede any generic git operation conventions.