readseek 0.8.20

readseek:
- docs: simplify ReadSeek documentation (Jarkko Sakkinen)
- release: update npm package integrity metadata (Jarkko Sakkinen)

pi-readseek:
- pi: clarify edit variant schema (Jarkko Sakkinen)
- docs: simplify ReadSeek documentation (Jarkko Sakkinen)
- release: update npm package integrity metadata (Jarkko Sakkinen)

opencode-readseek:
- release: update npm package integrity metadata (Jarkko Sakkinen)

claude-readseek:
- release: update npm package integrity metadata (Jarkko Sakkinen)

readseek.vim:
- Merged readseek.vim into this repository.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@iki.fi>