Linux has been my main workhorse since before the turn of the millenium, but I don't think a separate subforum for it would be useful here. (I voted No.)
While I agree with RoGeorge and bitwelder above, my reason is simpler: I do not see such a category being useful for anyone here. The current
Computers,
Embedded Computing,
Programming,
Networking and Wireless,
Security, and
General Technical Chat subforums suffice, because any relevant Linux-related question will fit into one of them, more or less.
For example, if you wanted to discuss how to best communicate with your embedded project and a Linux host, not having yet chosen any particular transport (Ethernet, WiFi, USB, RS-232, RS-422), the General Technical Chat might fit best if you wished to discuss different transports, or Embedded Computing if you wished to focus on the embedded aspects. For the software implementation, you'd pick Programming. If the information is sensitive, those aspects (including encryption and how it might be implemented) would go to Security. If you picked the wrong one, flag your own post, and ask moderators to move it.
To pick the correct subforum, look at the posts already posted in there, skimming the titles on first few pages, and reading any posts that might be similar or analogous to your own. (You should always do a search also, to find out if the issue has been discussed before. Both the forum search and external search engines like Google work for this.) It is still useful to mention that you use a Linux host, but it is just an implementation detail, a boundary condition, and not the focus or key of your questions.
For questions that involve Linux but no electronics, this is not the forum; those are elsewhere, like
LinuxQuestions for example. Similarly for Arduino/Raspberry Pi/etc. beginner programming questions.