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/reddit/README.md

@@ -0,0 +1,34 @@
+# Reddit Hand
+
+Autonomous Reddit manager -- monitors subreddits, posts content, replies to threads, and tracks karma and engagement.
+
+## Configuration
+
+| Field | Value |
+|-------|-------|
+| Category | `communication` |
+| Agent | `reddit-hand` |
+| Routing | `reddit`, `subreddit`, `reddit post`, `reddit monitor` |
+
+## Integrations
+
+- **REDDIT_CLIENT_ID** -- OAuth2 client ID from a Reddit app.
+- **REDDIT_CLIENT_SECRET** -- OAuth2 client secret from a Reddit app.
+- **REDDIT_USERNAME** -- Reddit account username.
+- **REDDIT_PASSWORD** -- Reddit account password.
+
+## Settings
+
+- **Subreddits** -- Comma-separated list of subreddits to monitor
+- **Monitor Mode** -- `hot_only`, `new_only`, `hot_and_new`, `rising`
+- **Auto Reply** -- Automatically reply to relevant posts (default: off)
+- **Post Frequency** -- `never`, `1_daily`, `3_daily`, `weekly`
+- **Content Style** -- `helpful`, `casual`, `expert`, `witty`
+- **Approval Mode** -- Queue posts for review (default: on)
+- **Max Reply Depth** -- `1`, `3`, `5`, `unlimited`
+
+## Usage
+
+```bash
+librefang hand run reddit
+```