openttd: add page (#5765)

pages/common/openttd.md

@@ -0,0 +1,32 @@
+# openttd
+
+> Open source clone of the Microprose game "Transport Tycoon Deluxe".
+> More information: <https://www.openttd.org>.
+
+- Start a new game:
+
+`openttd -g`
+
+- Load save game at start:
+
+`openttd -g {{path/to/file}}`
+
+- Start with the specified window resolution:
+
+`openttd -r {{1920x1080}}`
+
+- Start with a custom configuration file:
+
+`openttd -c {{path/to/file}}`
+
+- Start with selected video, sound, and music drivers:
+
+`openttd -v {{video_driver}} -s {{sound_driver}} -m {{music_driver}}`
+
+- Start a dedicated server, forked in the background:
+
+`openttd -f -D {{host}}:{{port}}`
+
+- Join a server with a password:
+
+`openttd -n {{host}}:{{port}}#{{player_name}} -p {{password}}`