feat: ability to specify id for container

[cyntler]

Hey @pradel! 👋
Please do a code review if you can ;)

Closes #483

[codecov]

Codecov Report

Merging #489 (c32ef80) into master (dcc0c74) will increase coverage by 0.02%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #489      +/-   ##
==========================================
+ Coverage   95.26%   95.28%   +0.02%     
==========================================
  Files           6        6              
  Lines         190      191       +1     
  Branches       69       69              
==========================================
+ Hits          181      182       +1     
  Misses          9        9              

Impacted Files	Coverage Δ
react-responsive-modal/src/index.tsx	100.00% <100.00%> (ø)

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[pradel]

Thanks!