docs(instr-http): document semantic conventions and attributes in use

[JamieDanielson]

Which problem is this PR solving?

I didn't see a specific issue for this, so realizing there should probably be another issue similar to open-telemetry/opentelemetry-js-contrib#1778 in this repo, for the instrumentations within.

This is intended to let folks know what version of semantic conventions are in use as well as the attributes exported in the instrumentation. This will make it easier to update to later versions when ready (see tracking issue #4572).

Short description of the changes

• In the README for http instrumentation, add version of Semantic Conventions used as well as a table of keys and values. I kept the "1.22+" because even though the numbered version will change with each release, right now it's effective in 1.22+ that contains the exported string keys. When we have a new semantic convention package with new attributes, we can adjust that.

Type of change

Please delete options that are not relevant.

• This change requires a documentation update

How Has This Been Tested?

• n/a

Checklist:

• Followed the style guidelines of this project
• Documentation has been updated

[codecov]

Codecov Report

Merging #4587 (fd72c9f) into main (f6a075b) will decrease coverage by 0.02%.
The diff coverage is n/a.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4587      +/-   ##
==========================================
- Coverage   92.84%   92.83%   -0.02%     
==========================================
  Files         328      328              
  Lines        9494     9494              
  Branches     2040     2040              
==========================================
- Hits         8815     8814       -1     
- Misses        679      680       +1     

see 1 file with indirect coverage changes