docs(BLE): updated obsolete README.md

[sylque]

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1. Please provide specific title of the PR describing the change, including the component name (eg. „Update of Documentation link on Readme.md“)
2. Please provide related links (eg. Issue which will be closed by this Pull Request)
3. Please update relevant Documentation if applicable
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Description of Change

The README.md page is obsolete. It does not take into account the fact that the BLE library is now part of arduino-esp32 core.

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[github-actions]

Warnings

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Some issues found for the commit messages in this PR: the commit message "Update README.md": summary looks empty type/action looks empty Please fix these commit messages - here are some basic tips: follow Conventional Commits style correct format of commit message should be: <type/action>(<scope/component>): <summary>, for example fix(esp32): Fixed startup timeout issue allowed types are: change,ci,docs,feat,fix,refactor,remove,revert,test sufficiently descriptive message summary should be between 20 to 72 characters and start with upper case letter avoid Jira references in commit messages (unavailable/irrelevant for our customers) TIP: Install pre-commit hooks and run this check when committing (uses the Conventional Precommit Linter).

👋 Hello sylque, we appreciate your contribution to this project!

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[pedrominatel]

LGTM