Update FlyterPropeller config to working config for flyte agent

[Sovietaced]

This pull request updates the flyte agent documentation to include working FlytePropeller configurations when running a custom agent/task. The previous configuration did not configure the agent service endpoint for propeller and attempts to run custom tasks would result in the following log messages. This also formats the YAML to 2 space indent.

❯ kubectl logs flytepropeller-5559db6f4d-bgpr7 -f | grep armada                                                                                                                                                            
{"json":{"exec_id":"f6bf36697f1a84994907","node":"examplesayhello","ns":"flytesnacks-development","res_ver":"32767965","routine":"worker-0","tasktype":"armada","wf":"flytesnacks:development:.flytegen.example.say_hello"},"level":"warning","msg":"No plugin found for Handler-type [armada], defaulting to [container]","ts":"2024-05-16T01:07:14Z"}
{"json":{"exec_id":"f6bf36697f1a84994907","node":"examplesayhello","ns":"flytesnacks-development","res_ver":"32767966","routine":"worker-0","tasktype":"armada","wf":"flytesnacks:development:.flytegen.example.say_hello"},"level":"warning","msg":"No plugin found for Handler-type [armada], defaulting to [container]","ts":"2024-05-16T01:07:14Z"}

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 61.10%. Comparing base (458da5c) to head (6190d59).
Report is 24 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5401      +/-   ##
==========================================
+ Coverage   61.07%   61.10%   +0.02%     
==========================================
  Files         793      793              
  Lines       51210    51156      -54     
==========================================
- Hits        31275    31257      -18     
+ Misses      17059    17027      -32     
+ Partials     2876     2872       -4     

Flag	Coverage Δ
unittests-datacatalog	69.31% <ø> (ø)
unittests-flyteadmin	58.90% <ø> (ø)
unittests-flytecopilot	17.79% <ø> (ø)
unittests-flytectl	68.31% <ø> (+0.33%)	⬆️
unittests-flyteidl	79.30% <ø> (+0.25%)	⬆️
unittests-flyteplugins	61.94% <ø> (ø)
unittests-flytepropeller	57.32% <ø> (ø)
unittests-flytestdlib	65.75% <ø> (ø)

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[Sovietaced]

#5460 should make this obsolete.