Add instructions for accessing frontend on localhost with a self-signed certificate

[yashhash2]

Fix #10947

changes

1. Added documentation to guide users on how to access the frontend on localhost with a self-signed certificate.
2. Included instructions for running Chrome in insecure mode on both macOS/Linux and Windows.
3. Added steps for disabling certificate checking in Firefox.
4. Provided a security note cautioning users to only use insecure browser modes for development purposes.

Checks

• The commit log is comprehensible. It follows 7 rules of great commit messages. We can fix this during merge by using a squash+merge if necessary
• Has tests or has a separate issue that describes the types of test that should be created. If no test is included it should explicitly be mentioned in the PR why there is no test.
• Is this PR adding logic based on one or more clinical attributes? If yes, please make sure validation for this attribute is also present in the data validation / data loading layers (in backend repo) and documented in File-Formats Clinical data section!
• Make sure your PR has one of the labels defined in https://github.com/cBioPortal/cbioportal/blob/master/.github/release-drafter.yml

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