Resolve "sso_quickstart.md is blank"

Docs Merge Request

Changes

• fixed hyperlink markdown syntax issue with quickstart.md
• sso_quickstart.md was accidentally deleted / made blank, reverted that change to restore it. (the following are additional changes after restoring the sso_quickstart.md, which won't correctly show up as a diff, since it was accidentally deleted.)
• updated logic so BIG_BANG_VERSION would reference a latest version instead of a pinned version, added a comment about how to pin to a version + the last version the guide was tested against.
• updated dependencies k3d, helm, kustomize, kubectl to same versions the quickstart.md had recently been updated to.
• updated k3d cluster create flags to account for breaking changes from k3d v4.x -> v5.x
• removed --values $HOME/bigbang/docs/example_configs/opa-overrides-k3d.yaml reference to external file, and instead embedded the contents of that file in the how to guide, should be more resilient incase the file ever gets renamed or moved.
• corrected a | sudo tee -a ~/.ssh/config --to be--> | tee -a ~/.ssh/config after realizing an edge case where it'd fail + that it wasn't needed.
• re-added valid wildcard ingress cert into keycloak's values (it had been moved to a new location, which means this how to guide was probably broken for a few months until this refresh occurred.)
• split some long markdown sections in 2, and removed apostrophes in some sections to improve ability to copy paste.

Note:

I did an E2E retest of the guide after finishing all commits / tweaks.

Preview of Changed markdown file

Current

https://repo1.dso.mil/platform-one/big-bang/bigbang/-/blob/master/docs/guides/deployment_scenarios/quickstart.md

Changes

https://repo1.dso.mil/platform-one/big-bang/bigbang/-/blob/1134-update-sso-quickstart/docs/guides/deployment_scenarios/sso_quickstart.md

For Issue

Closes #1134 (closed)