Fix information about delete's comment argument inside "supported commands" reference

[noisersup]

Description

Small fix.

Readiness checklist

• I added tests for new functionality or bugfixes.
• I ran task all, and it passed.
• I added/updated comments for both exported and unexported top-level declarations (functions, types, etc).
• I checked comments rendering with task godocs.
• I ensured that the title is good enough for the changelog.
• (for maintainers only) I set Reviewers (@FerretDB/core), Assignee, Labels, Project and project's Sprint fields.
• I marked all done items in this checklist.

[vercel]

Deployment failed with the following error:

Resource is limited - try again in 2 hours (more than 100, code: "api-deployments-free-per-day").

[codecov]

Codecov Report

Merging #1498 (46daaf7) into main (af2554a) will increase coverage by 0.00%.
The diff coverage is n/a.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1498   +/-   ##
=======================================
  Coverage   67.72%   67.72%           
=======================================
  Files         279      279           
  Lines       13492    13492           
=======================================
+ Hits         9137     9138    +1     
+ Misses       3431     3428    -3     
- Partials      924      926    +2     

Impacted Files	Coverage Δ
internal/handlers/tigris/tigrisdb/databases.go	66.66% <0.00%> (-7.70%)	⬇️
internal/util/version/version.go	48.52% <0.00%> (-4.42%)	⬇️
internal/handlers/common/filter.go	84.65% <0.00%> (ø)
internal/handlers/tigris/tigrisdb/errors.go	42.85% <0.00%> (ø)
internal/handlers/tigris/tigrisdb/collections.go	60.00% <0.00%> (+5.71%)	⬆️
internal/handlers/tigris/msg_create.go	74.64% <0.00%> (+7.04%)	⬆️

Flag	Coverage Δ
integration	63.80% <ø> (+<0.01%)	⬆️
mongodb	14.19% <ø> (-0.01%)	⬇️
pg	53.02% <ø> (-0.03%)	⬇️
tigris	36.10% <ø> (+<0.01%)	⬆️
unit	26.36% <ø> (-0.03%)	⬇️

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