Remove server-specific reverse proxy pages from ToC

[StackScribe]

Reduce length of table of contents by moving the server-specific reverse proxy pages

The "System Administration" section lists pages for six specific reverse proxy types, which helps to make that table of contents just too long!

Proposed solution:

• In https://www.jenkins.io/doc/book/system-administration/reverse-proxy-configuration-with-jenkins/ , change the "Configuration Examples" header to be "Configuration Examples by Server Type"
• That list contains links to the same pages that are listed in the left table of contenst
• The trick is to build the pages so they are accessible from the links but do not appear in the left frame

We think the solution is to build these server-specific pages from a sub-directory in the source tree rather than at the same level as "Reverse proxy configuration" and "Authenticating scripted clients."

We also need redirects created so that the existing pages automatically redirect to the new location. That will allow links from pages like the configuration as code plugin documentation to continue working.

[tanujdevops]

I have made the small change mentioned in this issue and added "by Server Type" and I have created the PR #5509 To completely close this issue, We will have to change the layouts of the files in this section. I am not sure how to exactly do it. But if someone guides me on how I can change the layout and which files I need to update, I'll do it ASAP.

[MarkEWaite]

See https://github.com/jenkins-infra/jenkins.io/pull/5509#issuecomment-1260815799 for suggestions

[krisstern]

Hi, I would like to complete the items in this issue for Hacktoberfest if no one is currently actively working on them.

[krisstern]

@StackScribe Should I make the six items collapsible under the Reverse proxy configuration item in the navigation on the left-hand side then?

[krisstern]

I have just submitted a PR to deal with this issue. Turns out the solution is not easy or straightforward at all, but is manageable, except for that part where it is somewhat difficult to add the page before and page after hyperlinks at the top, now that we have introduced a subsection concept. So a quick fix is to get rid of these for all subsections while keeping the index hyperlink so that we could return to the root of the Jenkins Handbook directly. It took me a few days to complete the necessary changes.