Small Style Updates

[colegoldsmith]

Lots of little styling issues I noticed. I'll try to list all that was fixed:

• Mobile left nav improvements
• Table purple border color removed
• Table striping now works
• Docsearch icon change
• New token changes added

[eric-schneider]

@colegoldsmith Have you looked into updating the size of the DocSearch modal? See https://datastax.slack.com/archives/C05Q75MQ6UC/p1696638343141439?thread_ts=1696575191.091319&cid=C05Q75MQ6UC

[colegoldsmith]

@eric-schneider Yep I changed the width of the modal in the previous PR I made! It now matches the width of the command palette in Astra, 720px