Fix default configuration

[everdrone]

• Fixes the default configuration generated by grab config generate to work out of the box
• Shorten README.md, move a more advanced configuration into docs/guide.md

[codecov-commenter]

Codecov Report

Merging #6 (cc657f3) into main (218914e) will increase coverage by 0.02%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main       #6      +/-   ##
==========================================
+ Coverage   81.90%   81.93%   +0.02%     
==========================================
  Files          24       24              
  Lines        1210     1212       +2     
==========================================
+ Hits          991      993       +2     
  Misses        186      186              
  Partials       33       33              

Impacted Files	Coverage Δ
cmd/generate.go	32.35% <100.00%> (+2.04%)	⬆️

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