Versioning doc update

[lalitb]

Changes

Please provide a brief description of the changes here.

Update Versioning.md for:

• Clarity on release policy as we would have a single release package containing SDK, API, and all exporters.
• Clarity on versioning, as we have a single version for the entire release.
• Clarity on ABI compatibility vs ABI breaking across releases.

For significant contributions please make sure you have completed the following items:

• CHANGELOG.md updated for non-trivial changes
• Unit tests have been added
• Changes in public API reviewed

[codecov]

Codecov Report

Merging #811 (08669d9) into main (f793e6e) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main     #811   +/-   ##
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  Coverage   96.19%   96.19%           
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  Files         153      153           
  Lines        6444     6444           
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  Hits         6198     6198           
  Misses        246      246           

[reyang]

LGTM.

[ThomsonTan]

Could we give an example here on inline namespace?

[lalitb]

Sorry seems i missed this comment. ABI versioning using inline namespace is handled here in the code:

opentelemetry-cpp/api/include/opentelemetry/version.h

Lines 13 to 14 in 5767f8e

	#define OPENTELEMETRY_BEGIN_NAMESPACE \
	namespace opentelemetry { inline namespace OPENTELEMETRY_CONCAT(v, OPENTELEMETRY_ABI_VERSION_NO) {

. Should I be adding reference to this ?

[ThomsonTan]

Yes, I think we could add a reference in the next doc update.