[BUG][R] Fix documentation in R package

[LiNk-NY]

It updates the mustache template and simplifies the linking in the documentation so that it works for "non-primitive" types. R is good at looking for the name of the page and by topic with the provided name so that the correct documentation page is displayed.

-#' @field op   \link[hcamatrixapi:v1_ComparisonFilterOperator]{  V1ComparisonFilterOperator  }  [optional]
+#' @field op   \link{V1ComparisonFilterOperator}  [optional]

There are still some unresolved issues concerning some "list" types that show up as array[class] but I didn't touch the code for these primitive types. I've run it for the r-petstore.sh and another API. The results are pretty satisfactory.

Reference issue: See #4428

I must say that there was some resistance from @Ramanth which was quite unhelpful because he did not provide concrete evidence to his claim. See: #4428 (comment)
I have tested the generation with the Jar file since and it is working.

Thanks.

PR checklist

• Read the contribution guidelines.
• If contributing template-only or documentation-only changes which will change sample output, build the project before.
• Run the shell script(s) under ./bin/ (or Windows batch scripts under.\bin\windows) to update Petstore samples related to your fix. This is important, as CI jobs will verify all generator outputs of your HEAD commit, and these must match the expectations made by your contribution. You only need to run ./bin/{LANG}-petstore.sh, ./bin/openapi3/{LANG}-petstore.sh if updating the code or mustache templates for a language ({LANG}) (e.g. php, ruby, python, etc).
• File the PR against the correct branch: master, 4.3.x, 5.0.x. Default: master.
• Copy the technical committee to review the pull request if your PR is targeting a particular programming language.

cc: @Ramanth @saigiridhar21

[auto-labeler]

👍 Thanks for opening this issue!
🏷 I have applied any labels matching special text in your issue.

The team will review the labels and make any necessary changes.

[wing328]

Thanks for the PR. Please run ./bin/r-petstore.sh or bin\windows\r-petstore.bat to udpate the samples so that the CI can test the change.

[LiNk-NY]

Thanks William @wing328 for all your help here and via email.
I ran ./bin/r-petstore.sh. Feel free to mark this PR as a bug fix rather than enhancement.

[Update]: It looks like the CI is having issues with setup
[Update2]: All clear 👍

Best,
Marcel

[wing328]

LGTM