feat: inc metrics for each command ran

[caarlos0]

this will be particularly useful for wishlist, but other apps might take advantage of it too...

This adds a command label to all metrics, and a way to customize what that value should be. By default, we get the first field of session.Command.

[codecov-commenter]

Codecov Report

Merging #14 (b7c251c) into main (3474078) will increase coverage by 1.52%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main      #14      +/-   ##
==========================================
+ Coverage   86.88%   88.40%   +1.52%     
==========================================
  Files           1        1              
  Lines          61       69       +8     
==========================================
+ Hits           53       61       +8     
  Misses          6        6              
  Partials        2        2              

Impacted Files	Coverage Δ
main.go	88.40% <100.00%> (+1.52%)	⬆️

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[aymanbagabas]

It would be cool to have a way to add custom metrics to the middleware.

[caarlos0]

It would be cool to have a way to add custom metrics to the middleware.

you can! You can simply add a new middleware that does what you want, or just register your metrics wherever you think it makes sense, so long they are added to the same registerer, everything should work :D