Update README with deprecation warning

[HDauven]

No description provided.

[codecov-commenter]

Codecov Report

Attention: 218 lines in your changes are missing coverage. Please review.

Comparison is base (57c6bbd) 40.18% compared to head (cb87888) 39.52%.
Report is 90 commits behind head on master.

❗ Current head cb87888 differs from pull request most recent head 4e5b34b. Consider uploading reports for the commit 4e5b34b to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1540      +/-   ##
==========================================
- Coverage   40.18%   39.52%   -0.66%     
==========================================
  Files         147      147              
  Lines        9651     9770     +119     
==========================================
- Hits         3878     3862      -16     
- Misses       5144     5278     +134     
- Partials      629      630       +1     

Files	Coverage Δ
pkg/config/genesis/config.go	0.00% <ø> (ø)
pkg/config/loader.go	59.03% <100.00%> (ø)
pkg/core/consensus/committee/handler.go	69.23% <100.00%> (-0.99%)	⬇️
pkg/core/consensus/reduction/testutil.go	50.00% <100.00%> (+1.66%)	⬆️
pkg/p2p/wire/encoding/miscdata.go	52.27% <ø> (-2.28%)	⬇️
pkg/p2p/wire/message/agreement.go	39.76% <100.00%> (-0.32%)	⬇️
pkg/config/genesis/presets.go	75.00% <50.00%> (+5.76%)	⬆️
pkg/core/chain/fallback.go	15.31% <75.00%> (ø)
pkg/core/consensus/agreement/handler.go	54.62% <80.00%> (ø)
...core/consensus/blockgenerator/candidate/genesis.go	0.00% <0.00%> (ø)
... and 26 more

... and 6 files with indirect coverage changes

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.