## Summary
Corrects a grammatical error in CONTRIBUTING.md line 36.
## Change
**Line 36**: `speed of which` → `speed at which`
The preposition "of" is incorrect when connecting the noun "speed" with
the relative pronoun "which". Standard English requires "at" (e.g., "the
speed at which", "the rate at which").
**Before:**
```
This will greatly help the priority setting and speed of which maintainers can get to your issue.
```
**After:**
```
This will greatly help the priority setting and speed at which maintainers can get to your issue.
```
Some updates to the documentation:
* Replace code-of-conduct with organization one.
* Cleanup `CONTRIBUTING.md`, `README.md` and `SECURITY.md` markdown.
* Remove `.txt` extension from `LICENSE` for consistency across repos.
Noritaka Kobayashi