docs: add README for every subdirectory

33 agent READMEs, 14 hand READMEs, 2 plugin READMEs
(echo-memory + hooks), and 2 skill READMEs
(custom-skill-prompt + custom-skill-python).

Each README documents the component's purpose, configuration,
and usage based on its TOML definition.

hands/clip/README.md

@@ -0,0 +1,31 @@
+# Clip Hand
+
+Turns long-form video into viral short clips with captions and thumbnails.
+
+## Configuration
+
+| Field | Value |
+|-------|-------|
+| Category | `content` |
+| Agent | `clip-hand` |
+| Routing | `clip video`, `video transcription`, `subtitle extraction`, `download video`, `short clip` |
+
+## Integrations
+
+- **FFmpeg** -- Core video processing engine for clips, captions, and thumbnails.
+- **FFprobe** -- Video metadata analyzer (ships with FFmpeg).
+- **yt-dlp** -- Downloads videos from YouTube, Vimeo, Twitter, and 1000+ sites.
+
+## Settings
+
+- **Speech-to-Text Provider** -- `auto`, `whisper_local`, `groq_whisper`, `openai_whisper`, `deepgram`
+- **Text-to-Speech Provider** -- `none`, `edge_tts`, `openai_tts`, `elevenlabs`
+- **Publish Clips To** -- `local_only`, `telegram`, `whatsapp`, `both`
+- **Telegram Bot Token / Chat ID** -- For Telegram publishing
+- **WhatsApp Token / Phone ID / Recipient** -- For WhatsApp publishing
+
+## Usage
+
+```bash
+librefang hand run clip
+```