Add troubleshooting section

README.md

@@ -63,6 +63,11 @@ It runs on Linux, macOS, Raspberry Pi, BSD, Cygwin, Linux subsystem for Windows
   - [Help](#help)
 - [Quickstart](#quickstart)
 - [How to](#how-to)
+- [Troubleshooting](#troubleshooting)
+  - [tmux configuration](#tmux-configuration)
+  - [BSD terminal issue](#bsd-terminal-issue)
+  - [restrict file open](#restrict-file-open)
+  - [restrict 0-byte files](#restrict-0-byte-files)
 - [Why fork?](#why-fork)
 - [Mentions](#mentions)
 - [Developers](#developers)
@@ -406,6 +411,30 @@ To lookup keyboard shortcuts at runtime, press <kbd>?</kbd>.
 
 Please visit the [How to](https://github.com/jarun/nnn/wiki/How-to) wiki page.
 
+#### TROUBLESHOOTING
+
+##### tmux configuration
+
+`nnn` might not handle keypresses correctly when used with tmux (see issue #104 for more details). Set `TERM=xterm-256color` to address it.
+
+##### BSD terminal issue
+
+By default in OpenBSD & FreeBSD, `stty` maps <kbd>^Y</kbd> to `DSUSP`. This means that typing <kbd>^Y</kbd> will suspend `nnn` as if you typed <kbd>^Z</kbd> (you can bring `nnn` back to the foreground by issuing `fg`) instead of entering multi-copy mode. You can check this with `stty -a`. If it includes the text `dsusp = ^Y`, issuing `stty dsusp undef` will disable this `DSUSP` and let `nnn` receive the <kbd>^Y</kbd> instead.
+
+##### restrict file open
+
+In order to disable opening files on accidental navigation key (<kbd>→</kbd> or <kbd>l</kbd>) press:
+
+    export NNN_RESTRICT_NAV_OPEN=1
+
+Use <kbd>Enter</kbd> to open files.
+
+##### restrict 0-byte files
+
+Restrict opening 0-byte files due to [unexpected behaviour](https://github.com/jarun/nnn/issues/187); use _edit_ or _open with_ to open the file.
+
+    export NNN_RESTRICT_0B=1
+
 #### WHY FORK?
 
 `nnn` was initially forked from [noice](http://git.2f30.org/noice/) but is significantly [different](https://github.com/jarun/nnn/wiki/nnn-vs.-noice) today. I chose to fork because: