docs: Update README with note on development setup instructions (#10108)

* docs: Update README with note on development setup instructions

* docs: Revise development environment setup instructions for clarity and organization

* Revise Quickstart note for repo cloning

Updated note about repo cloning in the Quickstart section.

* Update README for clarity and organization in Quickstart section

Refined installation and running instructions, added emphasis on local installation, and improved formatting for better readability. Included a caution note for Windows users regarding updates.

* Update README to streamline Quickstart instructions

Removed unnecessary header and improved clarity in the Quickstart section by consolidating the instructions for accessing the local server. This enhances readability and user experience.

* Enhance README Quickstart section for clarity and completeness

Updated installation instructions to improve clarity, added emphasis on local installation, and included additional details about running the Langflow server. Revised section headers for better organization and user experience.

* Add @mendonk suggestion

Co-authored-by: Mendon Kissling <59585235+mendonk@users.noreply.github.com>

* Improve devcontainer instruction, to @mendonk suggestion

Co-authored-by: Mendon Kissling <59585235+mendonk@users.noreply.github.com>

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Co-authored-by: Mendon Kissling <59585235+mendonk@users.noreply.github.com>