Significantly improve docs in README (partial)

[BooleanCat]

Please provide a brief description of the change.

Much improved docs for READ, well at least the beginnings of it. Will follow up with more changes to add more missing docs.

Which issue does this change relate to?

None.

Contribution checklist.

• [x] I have read and understood the CONTRIBUTING guidelines
• [x] All commits in my PR conform to the commit hygiene section
• [x] I have added relevant tests
• [x] I have not added any dependencies

Additional context

Within this change are a few others mixed in, my bad!

1. I removed TryCollect from itx for consistency.
2. I renamed Reduce to Fold. I'll later add a Fold variant called Reduce that uses the first item yielded as the initial value (just like Rust)

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 100.00%. Comparing base (5351fab) to head (75d4c5d).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #132 +/- ## ========================================= Coverage 100.00% 100.00% ========================================= Files 32 32 Lines 407 405 -2 ========================================= - Hits 407 405 -2 ```

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