Add resize mode to config

These are the default keybindings in i3.

config

@@ -142,6 +142,30 @@ output * bg /usr/share/sway/Sway_Wallpaper_Blue_1920x1080.png fill
     # Show the next scratchpad window or hide the focused scratchpad window.
     # If there are multiple scratchpad windows, this command cycles through them.
     bindsym $mod+minus scratchpad show
+#
+# Resizing containers:
+#
+mode "resize" {
+    # left will shrink the containers width
+    # right will grow the containers width
+    # up will shrink the containers height
+    # down will grow the containers height
+    bindsym $left resize shrink width 10 px or 10 ppt
+    bindsym $down resize grow height 10 px or 10 ppt
+    bindsym $up resize shrink height 10 px or 10 ppt
+    bindsym $right resize grow width 10 px or 10 ppt
+
+    # ditto, with arrow keys
+    bindsym Left resize shrink width 10 px or 10 ppt
+    bindsym Down resize grow height 10 px or 10 ppt
+    bindsym Up resize shrink height 10 px or 10 ppt
+    bindsym Right resize grow width 10 px or 10 ppt
+
+    # return to default mode
+    bindsym Return mode "default"
+    bindsym Escape mode "default"
+}
+bindsym $mod+r mode "resize"
 
 #
 # Status Bar: