Changelog and compatibility map update

[alpe]

Changelog + Readme update

[codecov]

Codecov Report

Merging #637 (4c4874c) into master (08ee11d) will increase coverage by 0.03%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #637      +/-   ##
==========================================
+ Coverage   60.21%   60.24%   +0.03%     
==========================================
  Files          48       48              
  Lines        5313     5313              
==========================================
+ Hits         3199     3201       +2     
+ Misses       1889     1888       -1     
+ Partials      225      224       -1     

Impacted Files	Coverage Δ
x/wasm/keeper/keeper.go	87.30% <0.00%> (+0.33%)	⬆️

[ethanfrey]

perfect.
we will wait for 1.0.0-beta to tag the final v0.20.0 so maybe you can just update the compatibility table to that non existent version.

We can tag a v0.20.0-rc first, but I will wait for the dependency to be ready before making v0.20 final