Switch to better maintained spellcheck library

[wesbiggs]

Problem

yaspeller appears to be unmaintained, and was causing https://githubcom/LibertyDSNP/spec/security/dependabot/39.

Solution

spellchecker-cli is used instead; it works very similarly.

Change summary:

• [ ] Updated speller and regenerated dictionary and config files
• [ ] Fixed a handful of issues the new speller found that the old one did not

Steps to Verify:

1. Run npm install, then npm run lint or npm run spellcheck