[Fix] Fix typos in the semilearn package, README.md, and train.py.

[adamtupper]

What does this PR do?

This PR fixes typos in the main semilearn package, and the README.md and train.py files.

Does your PR introduce any breaking changes? If yes, please list them.

No. The changes only effect comments and strings, with few exceptions (specifically, the FreeMatchThresholdingHook class name and the prefetch_time metric name).

Before submitting

• [ ] Was this discussed/approved via a GitHub issue? (not for typos and docs)
• [x] Did you read the contributor guideline, Pull Request section?
• [x] Did you make sure your PR does only one thing, instead of bundling different changes together?
• [x] Did you make sure to update the documentation with your changes? (if necessary)
• [x] Did you list all the breaking changes introduced by this pull request?

PR review

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[adamtupper]

@microsoft-github-policy-service agree

On Jul 24, 2023, at 16:39, microsoft-github-policy-service[bot] @.***> wrote:

@microsoft-github-policy-service agree