chore: add CHANGELOG.md

[mayurkale22]

Which problem is this PR solving?

• Closes Add CHANGELOG.md #557

[codecov-io]

Codecov Report

Merging #574 into master will decrease coverage by 0.13%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #574      +/-   ##
==========================================
- Coverage   90.67%   90.54%   -0.14%     
==========================================
  Files         154      155       +1     
  Lines        8110     8038      -72     
  Branches      703      705       +2     
==========================================
- Hits         7354     7278      -76     
- Misses        756      760       +4

Impacted Files	Coverage Δ
...ages/opentelemetry-plugin-http/test/utils/utils.ts	33.33% <0%> (-26.67%)	⬇️
...es/opentelemetry-node/src/instrumentation/utils.ts	90.47% <0%> (-9.53%)	⬇️
...ges/opentelemetry-tracing/src/NoopSpanProcessor.ts	66.66% <0%> (-8.34%)	⬇️
.../opentelemetry-plugin-redis/test/assertionUtils.ts	95.83% <0%> (-4.17%)	⬇️
...pentelemetry-plugin-http/test/utils/httpRequest.ts	90.9% <0%> (ø)	⬆️
...telemetry-plugin-document-load/src/documentLoad.ts	98.13% <0%> (ø)	⬆️
...entelemetry-exporter-jaeger/test/transform.test.ts	100% <0%> (ø)	⬆️
packages/opentelemetry-tracing/src/config.ts	100% <0%> (ø)	⬆️
packages/opentelemetry-plugin-redis/src/utils.ts	90.9% <0%> (ø)	⬆️
packages/opentelemetry-tracing/src/utility.ts	100% <0%> (ø)	⬆️
... and 31 more