improve lychee config (again), fix links in customize section

[hazel-nut]

description

this PR tweaks the newly-improved lychee config:

• stops accepting 302, 307, 403, and 429 by default because doing so loses signal on actual broken links.
• adds additional domains that throw errors not related to broken links, like npmjs aggressively 403ing all bots and anchor links on dynamic pages.
• changes cache to only store successful status code responses to avoid re-testing known valid links while fixing links locally

and then i fixed all the links in the /customize section of the docs. 🙂

testing

one test is the results of lychee on this PR! unfortunately the salesforce links sometimes redirect with language locale and then sometimes also redirect back ... not sure what to do about that.

you can also test by running lychee locally against the customize section. from the root of the repo:

lychee -c lychee.toml main/docs/customize/**/*.mdx

you'll probably see a few 503s from core.telegram.org because okta blocks the domain (but the URLs do work). you'll also see a 404 for the auth0-aws github repo, but there's no replacement link because the repo was deleted. i erred on the side of not deprecating a half dozen content articles in this PR to avoid scope creep, but we probably should.

[github-actions]

Summary

Status	Count
🔍 Total	402
✅ Successful	147
⏳ Timeouts	0
🔀 Redirected	3
👻 Excluded	251
❓ Unknown	0
🚫 Errors	0
⛔ Unsupported	1

Redirects per input

Redirects in main/docs/customize/integrations/marketing-tool-integrations/salesforce-marketing-cloud.mdx

• [200] https://help.salesforce.com/s/articleView?id=mktg.mc_es_get_started_checklist_for_email_studio.htm&type=5 | Redirect: Followed 1 redirect resolving to the final status of: OK. Redirects: https://help.salesforce.com/s/articleView?id=mktg.mc_es_get_started_checklist_for_email_studio.htm&type=5 --> https://help.salesforce.com/s/articleView?language=en_US&id=mktg.mc_es_get_started_checklist_for_email_studio.htm&type=5
• [200] https://help.salesforce.com/s/articleView?id=mktg.mc_es_import_subscribers_from_file.htm&type=5 | Redirect: Followed 1 redirect resolving to the final status of: OK. Redirects: https://help.salesforce.com/s/articleView?id=mktg.mc_es_import_subscribers_from_file.htm&type=5 --> https://help.salesforce.com/s/articleView?language=en_US&id=mktg.mc_es_import_subscribers_from_file.htm&type=5
• [200] https://help.salesforce.com/s/articleView?id=xcloud.faq_import_general_permissions.htm&type=5 | Redirect: Followed 1 redirect resolving to the final status of: OK. Redirects: https://help.salesforce.com/s/articleView?id=xcloud.faq_import_general_permissions.htm&type=5 --> https://help.salesforce.com/s/articleView?language=en_US&id=xcloud.faq_import_general_permissions.htm&type=5
  Full Github Actions output

[hazel-nut]

oops. all the auth0.com/docs link barking should quiet down once #370 is in. but i've temporarily excluded it in 9bc189e and will remove that exclusion in the other PR.