Simple, lightweight, and portable command-line i3-wm and i3-gaps cheat sheet, supporting the ability to filter output.
Unfortunately, CSi3 may not work on everyone's configuration file. If you have standard 'config' syntax, it should work swimmingly. For an example of a configuration file with which CSi3 well behaves, check out my i3Config repository here on my GitHub. Modes are not currently (if ever) supported; although the bindings should be listed, it would be without the context of the mode.
Installation can be done with Cito. Your best bet, however, is to install via CSi3's installation script.
For a quick terminal one-liner, using the aforementioned installation script, you should be able to execute the following, assuming you have sudo(8):
(cd /tmp; curl -so csi3-installer 'https://raw.githubusercontent.com/terminalforlife/Extra/master/source/csi3/csi3-installer' && sudo \sh csi3-installer; rm csi3-installer)If that fails, you probably don't have curl(1), so try wget(1):
(cd /tmp; wget -qO csi3-installer 'https://raw.githubusercontent.com/terminalforlife/Extra/master/source/csi3/csi3-installer' && sudo \sh csi3-installer; rm csi3-installer)If you don't have sudo(8), just omit it from the command(s) above, and run them as the root user, however you gain such privileges.
If you've used the installer, then you can run the following to delete the files it creates:
sudo rm -v /usr/share/man/man1/csi3.1.gz /usr/share/bash-completion/completions/csi3 /usr/bin/csi3
If you don't have sudo(8), you'll have to acquire root privileges by other means.