urxvt: add page (#3294)

pages/linux/urxvt.md

@@ -0,0 +1,24 @@
+# urxvt
+
+> Rxvt-unicode.
+> A customizable terminal emulator.
+
+- Open a new urxvt window:
+
+`urxvt`
+
+- Run in a specific directory:
+
+`urxvt -cd {{path/to/directory}}`
+
+- Run a command in a new urxvt window:
+
+`urxvt -e {{command}}`
+
+- Run a command and keep the window open:
+
+`urxvt --hold -e {{command}}`
+
+- Run a command within the "sh" shell:
+
+`urxvt -e {{sh}} -c {{command}}`