Metrics doc

[iGxnon]

Please briefly answer these questions:

• what problem are you trying to solve? (or if there's no problem, what's the motivation for this change?)

• Change quick start
• Fix benchmark

• what changes does this pull request make?

• are there any non-obvious implications of these changes? (does it break compatibility with previous versions, etc)

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 56.41026% with 17 lines in your changes are missing coverage. Please review.

Project coverage is 75.49%. Comparing base (e35b35a) to head (239b85c). Report is 84 commits behind head on master.

Files	Patch %	Lines
crates/curp/src/server/metrics.rs	62.50%	12 Missing :warning:
crates/curp/src/server/raw_curp/mod.rs	0.00%	3 Missing :warning:
crates/curp/src/server/curp_node.rs	0.00%	2 Missing :warning:

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #685      +/-   ##
==========================================
- Coverage   75.55%   75.49%   -0.06%     
==========================================
  Files         180      186       +6     
  Lines       26938    27478     +540     
  Branches    26938    27478     +540     
==========================================
+ Hits        20353    20745     +392     
- Misses       5366     5458      +92     
- Partials     1219     1275      +56     

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

[iGxnon]

/cc @bsbds Could you take a look?

[mergify[bot]]

@iGxnon Convert your pr to draft since CI failed

[Phoenix500526]

@Mergifyio rebase

[mergify[bot]]

rebase

✅ Branch has been successfully rebased

[mergify[bot]]

@iGxnon Convert your pr to draft since CI failed

[iGxnon]

rebased manually

[mergify[bot]]

@iGxnon Your PR is in conflict and cannot be merged.