Update 'README.md'

README.md

@@ -1,3 +1,19 @@
 # dotfiles
 
-Public config files
+Public config files
+
+## Install tmux
+
+```bash
+sudo apt install tmux
+git clone https://github.com/tmux-plugins/tpm ~/.tmux/plugins/tpm
+```
+
+Then start tmux and press `prefix` + <kbd>I</kbd>.
+
+## Install Oh-my-posh
+
+```bash
+sudo wget https://github.com/JanDeDobbeleer/oh-my-posh/releases/latest/download/posh-linux-arm -O /usr/local/bin/oh-my-posh
+sudo chmod +x /usr/local/bin/oh-my-posh
+```