docs: fix readme MetricProvider -> MeterProvider

[aabmass]

Which problem is this PR solving?

• Readme typo

Short description of the changes

• fix MetricProvider to MeterProvider

[codecov]

Codecov Report

Merging #1791 (79c9e9b) into master (6b5d347) will increase coverage by 0.40%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #1791      +/-   ##
==========================================
+ Coverage   91.78%   92.18%   +0.40%     
==========================================
  Files         149      165      +16     
  Lines        4660     5595     +935     
  Branches     1011     1206     +195     
==========================================
+ Hits         4277     5158     +881     
- Misses        383      437      +54     

Impacted Files	Coverage Δ
...emetry-core/src/platform/node/RandomIdGenerator.ts	87.50% <0.00%> (-6.25%)	⬇️
...es/opentelemetry-context-zone-peer-dep/src/util.ts	100.00% <0.00%> (ø)
packages/opentelemetry-plugin-fetch/src/fetch.ts	96.55% <0.00%> (ø)
...kages/opentelemetry-web/src/StackContextManager.ts	97.05% <0.00%> (ø)
.../opentelemetry-exporter-collector/src/transform.ts	85.47% <0.00%> (ø)
...ry-context-zone-peer-dep/src/ZoneContextManager.ts	85.18% <0.00%> (ø)
...emetry-instrumentation-xml-http-request/src/xhr.ts	96.79% <0.00%> (ø)
packages/opentelemetry-web/src/utils.ts	94.70% <0.00%> (ø)
...telemetry-plugin-fetch/src/enums/AttributeNames.ts	100.00% <0.00%> (ø)
...ntelemetry-web/src/enums/PerformanceTimingNames.ts	100.00% <0.00%> (ø)
... and 9 more