Truncate blog post display

[Fashander]

Description

Readiness checklist

• I added/updated unit tests.
• I added/updated integration/compatibility tests.
• I added/updated comments and checked rendering.
• I made spot refactorings.
• I updated user documentation.
• I ran task all, and it passed.
• I ensured that PR 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.

[codecov]

Codecov Report

Merging #1874 (9519f4c) into main (44b7b0a) will increase coverage by 0.05%.
The diff coverage is n/a.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1874      +/-   ##
==========================================
+ Coverage   70.05%   70.11%   +0.05%     
==========================================
  Files         310      310              
  Lines       15236    15236              
==========================================
+ Hits        10673    10682       +9     
+ Misses       3588     3579       -9     
  Partials      975      975              

Impacted Files	Coverage Δ
internal/handlers/common/filter.go	84.65% <0.00%> (ø)
internal/handlers/pg/pgdb/database_metadata.go	85.54% <0.00%> (+3.61%)	⬆️
internal/handlers/pg/pgdb/collections.go	69.29% <0.00%> (+4.72%)	⬆️

Flag	Coverage Δ
integration	66.48% <ø> (ø)
mongodb	14.63% <ø> (ø)
pg	55.21% <ø> (ø)
tigris	45.28% <ø> (ø)
unit	28.31% <ø> (+0.20%)	⬆️

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