Make Python doc pages local

[chalin]

• Contributes to Migrate Python docs to this repo #1109
• The pages are copied from the Python repo's website_docs folder (https://github.com/open-telemetry/opentelemetry-python/tree/main/website_docs).
• There are no changes in the generated site files, except for timestamps and the Git commit hash for the pages:

  $ (cd public && git diff -b -w --ignore-blank-lines -I "dateModified|modified_time" -- . ':(exclude)*.xml')

  diff --git a/docs/instrumentation/python/getting-started/index.html b/docs/instrumentation/python/getting-started/index.html
  index 1040be91..611e3063 100644
  --- a/docs/instrumentation/python/getting-started/index.html
  +++ b/docs/instrumentation/python/getting-started/index.html
  @@ -1042,6 +1042,9 @@ with tracer.start_as_current_span("foo"):
   </code></pre>
          
          
  +       <div class="text-muted mt-5 pt-3 border-top">
  +  Last modified February 8, 2022: <a href="/open-telemetry/opentelemetry.io/commit/ce4807007d633d11f16d1bb448e228fd0869bf25">Add pages (ce48070)</a>
  +</div>
   
   </div>
   
  diff --git a/docs/instrumentation/python/index.html b/docs/instrumentation/python/index.html
  index a2b5e68d..76a59d63 100644
  --- a/docs/instrumentation/python/index.html
  +++ b/docs/instrumentation/python/index.html
  @@ -793,6 +793,9 @@ is as follows:</p>
   
          
          
  +       <div class="text-muted mt-5 pt-3 border-top">
  +  Last modified February 8, 2022: <a href="/open-telemetry/opentelemetry.io/commit/ce4807007d633d11f16d1bb448e228fd0869bf25">Add pages (ce48070)</a>
  +</div>
   
   </div>

Preview: https://deploy-preview-1111--opentelemetry.netlify.app/docs/instrumentation/python/