Update Log
**Listings:**
- Create `class ListingGenerator` with `__aiter__` and async `__anext__` methods to perform requests in the container.
- Update `class Listing` to support `class Message`.
- Implement `Streamable.streamable` decorator that makes (a)sync functions returning iterables or generators streamable.
**Inbox:**
- Implement `class Message` for inbox messages.
- Implement `AuthenticatedUser.inbox()`, `sent()` and `unread()` listing generators.
**Item Creation:**
- Implement `Subreddit.submit()` and add `enum SubmissionKind` (Thanks SpyrosRoum!)
- Create `Replyable` mixin used by `class Comment`, `class Submission`, `class Message`.
**Other:**
- `aPRAWBase.fullname` auto-property returns ID if kind is unknown.
- Optimize imports by importing `API_PATH` from `const.py`.
- `class Comment` only sets URL if `permalink` present in `data`.
- Use raw docstrings in cases where "\*\*" escape sequence is used.
- Make `Submission.morechildren()` async generator.
- Read `praw.ini` file intelligently (Thanks H4CKY54CK!)
**Tests:**
- Update listing tests.
- Add `test_submission_reply`.
- Add `test_subreddit_submit` (Thanks SpyrosRoum!) and `test_subreddit_random`.
- Add `test_user_inbox`, `test_user_unread`, `test_user_sent`.
- Add `test_streamable` unit tests.
**Documentation:**
- Add `SubredditWiki` documentation page.
- Add `Streamable` documentation page.