DOC-4423: add TCEs for various command pages

[dwdougherty]

DOC-4423

Python and JavaScript tabbed code examples for the above ticket. N.B. this PR will sit until at least one of the client repo PRs is merged.

[github-actions]

Staging links:
https://redis.io/docs/staging/DOC-4423-tces-for-cmd-pages/commands/auth/
https://redis.io/docs/staging/DOC-4423-tces-for-cmd-pages/commands/flushall/
https://redis.io/docs/staging/DOC-4423-tces-for-cmd-pages/commands/hgetall/
https://redis.io/docs/staging/DOC-4423-tces-for-cmd-pages/commands/hvals/
https://redis.io/docs/staging/DOC-4423-tces-for-cmd-pages/commands/info/
https://redis.io/docs/staging/DOC-4423-tces-for-cmd-pages/commands/llen/
https://redis.io/docs/staging/DOC-4423-tces-for-cmd-pages/commands/lpop/
https://redis.io/docs/staging/DOC-4423-tces-for-cmd-pages/commands/lpush/
https://redis.io/docs/staging/DOC-4423-tces-for-cmd-pages/commands/lrange/
https://redis.io/docs/staging/DOC-4423-tces-for-cmd-pages/commands/rpop/
https://redis.io/docs/staging/DOC-4423-tces-for-cmd-pages/commands/rpush/
https://redis.io/docs/staging/DOC-4423-tces-for-cmd-pages/commands/sadd/
https://redis.io/docs/staging/DOC-4423-tces-for-cmd-pages/commands/smembers/

[dwdougherty]

Thank you, @cmilesb!