docs: link to HttpApi from "Event source types"

[justinmk3]

Issue #, if available:
followup to #1290

Description of changes:
Minor fix for missing item in table of contents.

Description of how you validated changes:
Manual validation

Checklist:

• Write/update tests
• make pr passes
• Update documentation
• Verify transformed template deploys and application functions as expected

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[codecov-commenter]

Codecov Report

Merging #1649 into develop will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff            @@
##           develop    #1649   +/-   ##
========================================
  Coverage    94.10%   94.10%           
========================================
  Files           86       86           
  Lines         5408     5408           
  Branches      1080     1080           
========================================
  Hits          5089     5089           
  Misses         148      148           
  Partials       171      171           

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[justinmk3]

@mgrandis @awood45 @CoshUS @mingkun2020 is anything blocking this? It's a minor change but is confusing for someone reading the reference. And I don't see where the friction is that has delayed merging it.

[mgrandis]

Hey @justinmk3, let me take a look at this

[mgrandis]

It seems there was an error with AppVeyor and we are blocked for now.
Could you please try pushing a new commit to see if it unblocks it?
A minor change, like changing the logical id from line 391 to logical ID.

[justinmk3]

Rebased

[mgrandis]

Thanks @justinmk3 !