Update README.md

[emmyoop]

Problem

https://github.com/dbt-labs/dbt-jsonschema has not always been updated when schemas change.

Solution

Add a note in the README.

Checklist

• I have read the contributing guide and understand what's expected of me
• I have run this code in development and it appears to resolve the stated issue
• This PR includes tests, or tests are not required/relevant for this PR
• This PR has no interface changes (e.g. macros, cli, logs, json artifacts, config files, adapter interface, etc) or this PR has already received feedback and approval from Product or DX
• This PR includes type annotations for new and modified functions

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 88.81%. Comparing base (4ea0e10) to head (bd3aeb8).

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #10420      +/-   ##
==========================================
+ Coverage   88.74%   88.81%   +0.06%     
==========================================
  Files         180      180              
  Lines       22558    22558              
==========================================
+ Hits        20019    20034      +15     
+ Misses       2539     2524      -15     

Flag	Coverage Δ
integration	86.16% <ø> (+0.15%)	⬆️
unit	62.09% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Components	Coverage Δ
Unit Tests	62.09% <ø> (ø)
Integration Tests	86.16% <ø> (+0.15%)	⬆️

[ChenyuLInx]

thanks!