docs: Add Sub function example to pseudo parameters doc.

[walery]

Update documentation for change added in #8279

[codecov]

Codecov Report

Merging #8885 (39a26e2) into master (61dd3bd) will decrease coverage by 0.03%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #8885      +/-   ##
==========================================
- Coverage   87.72%   87.69%   -0.04%     
==========================================
  Files         266      266              
  Lines        9907     9907              
==========================================
- Hits         8691     8688       -3     
- Misses       1216     1219       +3     

Impacted Files	Coverage Δ
lib/plugins/aws/provider.js	94.77% <ø> (ø)
lib/plugins/aws/deploy/lib/checkForChanges.js	95.68% <0.00%> (-2.59%)	⬇️

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[pgrzesik]

Thank you @walery, unfortunately I think the proposed example is misleading, as it's not going to be a valid part of serverless.yml if that was the intention. Maybe it would be better to use something like

functions:
  hello:
    handler: my-function.handler
    environment:
      var: !Sub arn:aws:logs:${AWS::Region}:${AWS::AccountId}:log-group:/aws/lambda/*:*:*'

Please let me know what do you think 🙇

[walery]

Yes, I thought about it as well. Then I decided to use the same example as above.

Let me fix both examples 👍

[pgrzesik]

Oh, I didn't notice that the example above is also wrong - if you could adjust them both that would be perfect. Thank you 🙇

[walery]

I've now adjusted both examples. Thank you @pgrzesik

[pgrzesik]

Awesome job @walery - thanks for not only expanding docs but also improving old misleading example 🙇