Update the doc link and add the example link to the cutom policy guide

[ramya-bangera]

1. What this PR does / why we need it:
   Initially this check was added as the custom template creation via TMC TF provider was not supported. Now since the provider supports creation of the custom template removing this check,
   to let user create the custom template and assign it to custom policy on the fly.

2. Which issue(s) this PR fixes

    (optional, in `fixes #<issue number>` format, will close the issue(s) when PR gets merged):
   
    Fixes #
   

3. Additional information

4. Special notes for your reviewer

[codecov-commenter]

Codecov Report

Attention: 5 lines in your changes are missing coverage. Please review.

Comparison is base (cb65605) 25.40% compared to head (4c9b895) 25.39%.
Report is 2 commits behind head on main.

Files	Patch %	Lines
...ces/policy/kind/custom/recipe/tmc_custom_schema.go	0.00%	5 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #378      +/-   ##
==========================================
- Coverage   25.40%   25.39%   -0.01%     
==========================================
  Files         195      195              
  Lines       16784    16788       +4     
==========================================
  Hits         4264     4264              
- Misses      12302    12306       +4     
  Partials      218      218              

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[vmw-vjn]

Custom policy template and custom policy examples in doc seem to be scattered.

[shobha2626]

Overall LGTM, hope the doc changes are tested using the tool for doc preview

[github-actions]

I'm going to lock this pull request because it has been closed for 30 days. This helps our maintainers find and focus on the active issues.

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