chore(getting-started): Added a TypeScript version for Getting Started Guide

[nstawski]

Which problem is this PR solving?

• TS Getting started guide #586 Adding TS starting guide

Short description of the changes

• Added a new guide and examples for TypeScript; added links to the original README

[codecov-io]

Codecov Report

Merging #673 into master will decrease coverage by 5.13%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #673      +/-   ##
==========================================
- Coverage   94.97%   89.83%   -5.14%     
==========================================
  Files         187      213      +26     
  Lines        8867    10177    +1310     
  Branches      771      933     +162     
==========================================
+ Hits         8421     9143     +722     
- Misses        446     1034     +588

Impacted Files	Coverage Δ
packages/opentelemetry-core/test/utils/url.test.ts	50% <0%> (-50%)	⬇️
...pentelemetry-core/test/internal/validators.test.ts	50% <0%> (-50%)	⬇️
...elemetry-core/test/trace/spancontext-utils.test.ts	55.55% <0%> (-44.45%)	⬇️
...lemetry-core/test/trace/ProbabilitySampler.test.ts	56.52% <0%> (-43.48%)	⬇️
...s/opentelemetry-core/test/trace/NoopTracer.test.ts	60% <0%> (-40%)	⬇️
...s/opentelemetry-core/test/context/B3Format.test.ts	63.39% <0%> (-36.61%)	⬇️
...ges/opentelemetry-core/test/trace/NoopSpan.test.ts	63.63% <0%> (-36.37%)	⬇️
...s/opentelemetry-core/test/trace/tracestate.test.ts	65.06% <0%> (-34.94%)	⬇️
...ntelemetry-core/test/trace/NoRecordingSpan.test.ts	71.42% <0%> (-28.58%)	⬇️
...ackages/opentelemetry-core/src/platform/node/id.ts	71.42% <0%> (-28.58%)	⬇️
... and 68 more

[mayurkale22]

Great work!

[dyladan]

I see the tracing.ts file, but I don't see where it is imported by app.ts.

[nstawski]

I see the tracing.ts file, but I don't see where it is imported by app.ts.

It is not, it is ran by a command ts-node -r ./tracing.ts app.ts as outlined in the guide.

[nstawski]

@dyladan @mayurkale22 re-requested the review.

[mayurkale22]

lgtm

[OlivierAlbertini]

LGTM. added few comments.