sslstrip: add page

[jimmychang851129]

• The page(s) are in the correct platform directories: common, linux, osx, windows, sunos, android, etc.
• The page(s) have at most 8 examples.
• The page description(s) have links to documentation or a homepage.
• The page(s) follow the content guidelines.
• The PR title conforms to the recommended templates.
• Version of the command being documented (if known):

[tldr-bot]

The build for this PR failed with the following error(s):

pages/linux/sslstrip.md:3: TLDR003 Descriptions should start with a capital letter
pages/linux/sslstrip.md:3: TLDR004 Command descriptions should end in a period
pages/linux/sslstrip.md:6: TLDR015 Example descriptions should start with a capital letter
pages/linux/sslstrip.md:18: TLDR005 Example descriptions should end in a colon with no trailing characters

Please fix the error(s) and push again.

[kbdharun]

Thanks for your contribution. I have some suggestions for this page.

[vitorhcl]

@kbdharun had an excellent idea and opened a PR to add an usage section in sslstrip's README.

However, I don't know when (and even if) it will be seen by the author because the last merged PR was 3 months ago.

I support using the official documentation on more info and, until @kbdharun's PR is merged, keeping a help example.

[vitorhcl]

LGTM after my suggestions