Refactor documentation to replace SSH references with TCP with TLS 1.2

[amathur-LT]

This pull request updates the LambdaTest documentation to reflect a change in the underlying protocol used by the LambdaTest Tunnel feature. Specifically, all references to "SSH (Secure Shell)" connections have been replaced with "TCP with TLS 1.2 secure connection" to accurately describe the new protocol used for secure tunneling. These changes improve clarity and ensure the documentation matches the current implementation.

Key documentation updates:

Protocol and Security Terminology Updates:

• Replaced all mentions of "SSH (Secure Shell)" with "TCP with TLS 1.2 secure connection" throughout the Linux and macOS local testing documentation, including setup steps, configuration instructions, and connection termination guidance. [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12]

Capability and Feature Descriptions:

• Updated the description of the tunnel capability in the Selenium advanced capabilities documentation to specify that it now establishes a "TCP with TLS 1.2 secure connection" instead of an SSH connection.
• Modified general tunnel feature descriptions to reference "Web Socket, TCP" instead of "Web Socket, HTTPS, SSH (Secure Shell)" protocols.

SEO and Keyword Adjustments:

• Changed SEO keywords in the tunnel documentation to reflect the new protocol, replacing SSH-related terms with "TCP with TLS 1.2 secure connection."

[4DvAnCeBoY]

Looks good to me