i3lock: add page (EN/pt_BR) (#4146)

pages/linux/i3lock.md

@@ -0,0 +1,24 @@
+# i3lock
+
+> Simple screen locker built for the i3 window manager.
+> More information: <https://i3wm.org/i3lock>.
+
+- Lock screen with a simple color background (rrggbb format):
+
+`i3lock -c {{0000ff}}`
+
+- Lock screen to a PNG background:
+
+`i3lock -i {{path/to/picture.png}}`
+
+- Disable the unlock indicator (removes feedback on keypress):
+
+`i3lock -u`
+
+- Display mouse pointer instead of hiding it ('default' for default pointer, 'win' for a MS Windows pointer):
+
+`i3lock -p {{default|win}}`
+
+- Lock screen to a PNG background displayed in multiple monitors, with enabled mouse pointer:
+
+`i3lock -i {{path/to/picture.png}} -p {{default|win}} -t`