Fixes various errors in the documentation

[bnonni]

Overview

There's a handful of places in the docs that go to dead links or paths.

Description

Wanted to update those docs to help others in the future.

How Has This Been Tested?

Since this is a purely markdown and comment change, I didn't write tests. Please let me know if I need to do that, as I'm happy to do so.

Checklist

Tagging @decentralgabe @andresuribe87 since I've been communicating with them regarding these changes
Before submitting this PR, please make sure:

• I have read the CONTRIBUTING document.
• My code is consistent with the rest of the project
• I have tagged the relevant reviewers and/or interested parties
• I have updated the READMEs and other documentation of affected packages

References

Docs changed:

• README.md#vision-features-and-development: link to SIPs
• README.md#configuration: link to sample config files
• README.m#authentication-and-authorization: the paragraph in this section references pkg/middleware/Authentication.go but the file for setting up auth is actually pkg/server/middleware/authn.go
• README.md#health-and-readiness-checks: cleaned up the code examples for health check and readiness api calls
• README.md#health-and-readiness-checks: there is no config.toml file; I changed the language and linked it to config/dev.toml
• toml.md: various edits, some unclear; I improvised as needed, please review and revise
• kms.md: clarified how to create a key in GCP KMS
• auth.md: fixed broken link to Gin framework; adding clarifying steps for setting up and using AuthMiddleware
• server.go: adding clarifying commented out code for using AuthMiddleware

[andresuribe87]

Thanks so much! Couple of comments.

[decentralgabe]

thank you

[bnonni]

Thanks so much! Couple of comments.

Comments replied to. Changes pushed.

thank you

you're welcome. happy to help.