docs: Replace ampersand

[kevgo]

Proposed changes

Replace & with and since "identity and access proxy" reads better than "identity & access proxy" to me. This is an extract from #567, it makes sense to discuss this separately. Not feeling strongly about this. If the & is part of the branding we can leave it in.

Checklist

• I have read the contributing guidelines.
• I have read the security policy.
• I confirm that this pull request does not address a security
  vulnerability. If this pull request addresses a security. vulnerability, I
  confirm that I got green light (please contact
  security@ory.sh) from the maintainers to push
  the changes.
• I have added tests that prove my fix is effective or that my feature
  works.
• I have added or changed the documentation.

[kevgo]

Another reason for this change is that the old format leads to anchors containing double-dashes like
ory-oathkeeper-identity--access-proxy

[aeneasr]

Could you please address the merge conflicts? :)

[aeneasr]

Also keep in mind that we're using doctoc to generate the ToC - not sure if that was what generated the output! Also not sure if this is currently automated...

[zepatrik]

Pretty sure it's not automated....

[kevgo]

Merge conflicts resolved.

I was asking about doctoc automation in #748. Happy to look into automating it. Can we assume a Bash environment, i.e. find and xargs, or does this automation need to run on Windows as well?

[aeneasr]

Ah sorry, I must have overlooked that. Yeah - this would run on a ubuntu instance. I think it would make sense to have doctoc execution as part of maybe the docs/build pipeline. @zepatrik what you think?