(feat): Add support for Cloudflare KV storage and improve documentation

[AdiRishi]

Description

Resolves #159 #248

This PR is a major refactor of the codebase

• All storage operations are now done behind a generic StorageInterface
• The new storage interface is able to abstract both KV and R2, allowing for both backends to be used
• Major docs refresh, outlining both how to setup the project in a clearer way along with detailed guides on R2 and KV

How Has This Been Tested?

• This worker will be deployed under a "next" variant and will be used in production for a bit before the PR is merged

[changeset-bot]

🦋 Changeset detected

Latest commit: 572b52d

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
turborepo-remote-cache-cf	Major

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[github-actions]

🌩 Deploying with Cloudflare Pages

Name	Result
Last commit:	572b52d
Status:	✅ Deploy successful!
Preview URL:	https://a386edc0.cloudflare-turbo-cache-docs.pages.dev

[coveralls]

Pull Request Test Coverage Report for Build 7883229427

Details

• -2 of 288 (99.31%) changed or added relevant lines in 10 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+5.3%) to 98.185%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/storage/r2-storage.ts	76	78	97.44%

Totals
Change from base Build 7881285713:	5.3%
Covered Lines:	506
Relevant Lines:	508

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💛 - Coveralls