fancontrol: add page

[KristopherLeads]

• 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 page(s) follow the style guide.
• The PR title conforms to the recommended templates.
• Version of the command being documented (if known):

[KristopherLeads]

Fan automation utility from 16796. Note: this has a pretty complex config file that does most of the heavy lifting, but that can be found in the manpage - as such, this really only accepts one option, which is the path to the config file itself.

[tldr-bot]

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

pages/linux/fancontrol.md:8: TLDR103 Command example is missing its closing backtick

Please fix the error(s) and push again.

[Managor]

Is there a default configuration file location that get read if you run just fancontrol?

[CleanMachine1]

Once the suggestion above is approved, lgtm

[KristopherLeads]

Is there a default configuration file location that get read if you run just fancontrol?

Yes, /etc/fancontrol. Added the path into the page and made a second example for the custom path.