Fix typos in docs

[szepeviktor]

Description

Found a dozen misspellings in docs.

Corresponding issue:

htmx/CONTRIBUTING.md

Line 50 in 52f8076

1. Typo fixes in the documentation (not the code comments) are welcome, but formatting or debatable grammar changes will be automatically closed.

Checklist

• I have read the contribution guidelines
• I have targeted this PR against the correct branch (master for website changes, dev for
  source changes)
• This is either a bugfix, a documentation update, or a new feature that has been explicitly
  approved via an issue
• I ran the test suite locally (npm run test) and verified that it succeeded

https://github.com/crate-ci/typos

[Telroshan]

Thanks!

[szepeviktor]

Thank you for merging.

[szepeviktor]

There are only a handful of typos left.

./test/ws-sse/server.mjs:147:91: `visibile` -> `visible`
./test/core/shadowdom.js:74:16: `retrives` -> `retrieves`
./test/core/events.js:719:16: `Overriden` -> `Overridden`
./test/core/events.js:727:14: `Overriden` -> `Overridden`
./test/core/events.js:735:14: `Overriden` -> `Overridden`
./CHANGELOG.md:8:10: `degredation` -> `degradation`