README: A more engaging code snippet example

[omesser]

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As discussed in an issues in studio#6422) (private repo) - suggested some changes to this snippet:
copy-pasting motivation:

Yes - a working snippet is what I was driving it.
Looking at the snippet in the readme I suggest to consider updating maybe - that's why I looked at some competitors and compiled a new one before.

first order problem IMO is having a snippet that works out of the box
2nd order problem - polish how this snippet looks - so it's short and clean and nice, but also interesting.
things that bother me today a bit about the snippet from the readme(⚠️ : opinionated / style!):

• direct access to sys.argv (ugly)
• I can't run it "cleanly" -python train.py - fails in an ugly way (💭 mental mode - I'm just copy-pasting in "autopilot mental mode" to test studio - I don't want to have to make a decision about epoch parameter)
• 4 metrics/plots - train/eval is redundant (the same, also "eval called "val" ? 😖 )
• graphs aren't "interesting" to my taste (linear + noise):
  screenshot

  
  that's a personal "peeve" - it's not bad per-se, just that I saw an easy way to improve (from wandb, see below).
• exp finishes too quickly - had to run several times to "catch" the "liveness" of the metrics

Graphs for new snippet

screenshot

wdyt about this instead of the existing one @daavoo?

[daavoo]

I don't love that params don't have an effect nor change across runs, but not a blocker

[omesser]

Yes, this is a for a fake feel of familiarity / realism. But I've seen this in other places and I think since this is very very explicitly "fake" it's not misleading anyone (personal feel)

[codecov-commenter]

Codecov Report

Patch and project coverage have no change.

Comparison is base (d39bd1c) 89.53% compared to head (6712a54) 89.53%.

Additional details and impacted files

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  Misses        274      274           
  Partials       39       39           

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