docs: add npm badge [skip ci]

[tplooker]

Description

Adds NPM version badge to repository

• [ ] Tests for the changes have been added (for bug fixes / features)
• [x] The commit message(s) follow conventional commits
• [x] Documentation has been added / updated (for bug fixes / features)
• [x] Changes follow the contributing document.

Motivation and Context

Versioning clarity

Does this PR introduce a breaking change?

• [ ] Yes
• [x] No

Which merge strategy will you use?

• [x] Squash
• [ ] Rebase (REVIEW COMMITS)

[github-actions[bot]]

Total Coverage: 86.96%

Coverage Report

File	Branches	Funcs	Lines	Uncovered Lines
src
bbsSignature.ts	100%	72.73%	80.95%	140, 164, 217, 218, 219, 226, 237, 238, 255, 256, 257, 265
bls12381.ts	83.33%	100%	100%	26
bls12381toBbs.ts	100%	100%	100%
index.ts	100%	100%	100%
src/types
BlsKeyPair.ts	100%	100%	100%
index.ts	100%	100%	100%

[github-actions[bot]]

Total Coverage: 86.96%

Coverage Report

File	Branches	Funcs	Lines	Uncovered Lines
src
bbsSignature.ts	100%	72.73%	80.95%	140, 164, 217, 218, 219, 226, 237, 238, 255, 256, 257, 265
bls12381.ts	83.33%	100%	100%	26
bls12381toBbs.ts	100%	100%	100%
index.ts	100%	100%	100%
src/types
BlsKeyPair.ts	100%	100%	100%
index.ts	100%	100%	100%

[github-actions[bot]]

Total Coverage: 86.96%

Coverage Report

File	Branches	Funcs	Lines	Uncovered Lines
src
bbsSignature.ts	100%	72.73%	80.95%	140, 164, 217, 218, 219, 226, 237, 238, 255, 256, 257, 265
bls12381.ts	83.33%	100%	100%	26
bls12381toBbs.ts	100%	100%	100%
index.ts	100%	100%	100%
src/types
BlsKeyPair.ts	100%	100%	100%
index.ts	100%	100%	100%

[github-actions[bot]]

Total Coverage: 86.96%

Coverage Report

File	Branches	Funcs	Lines	Uncovered Lines
src
bbsSignature.ts	100%	72.73%	80.95%	140, 164, 217, 218, 219, 226, 237, 238, 255, 256, 257, 265
bls12381.ts	83.33%	100%	100%	26
bls12381toBbs.ts	100%	100%	100%
index.ts	100%	100%	100%
src/types
BlsKeyPair.ts	100%	100%	100%
index.ts	100%	100%	100%

[github-actions[bot]]

Total Coverage: 86.96%

Coverage Report

File	Branches	Funcs	Lines	Uncovered Lines
src
bbsSignature.ts	100%	72.73%	80.95%	140, 164, 217, 218, 219, 226, 237, 238, 255, 256, 257, 265
bls12381.ts	83.33%	100%	100%	26
bls12381toBbs.ts	100%	100%	100%
index.ts	100%	100%	100%
src/types
BlsKeyPair.ts	100%	100%	100%
index.ts	100%	100%	100%

[github-actions[bot]]

Total Coverage: 86.96%

Coverage Report

File	Branches	Funcs	Lines	Uncovered Lines
src
bbsSignature.ts	100%	72.73%	80.95%	140, 164, 217, 218, 219, 226, 237, 238, 255, 256, 257, 265
bls12381.ts	83.33%	100%	100%	26
bls12381toBbs.ts	100%	100%	100%
index.ts	100%	100%	100%
src/types
BlsKeyPair.ts	100%	100%	100%
index.ts	100%	100%	100%