Merge branch 'master' into jgrpp

# Conflicts:
#	cmake/SourceList.cmake
#	src/build_vehicle_gui.cpp
#	src/company_gui.cpp
#	src/console_cmds.cpp
#	src/depot_base.h
#	src/elrail.cpp
#	src/network/core/udp.cpp
#	src/network/network_admin.cpp
#	src/network/network_chat_gui.cpp
#	src/network/network_gui.cpp
#	src/network/network_server.cpp
#	src/newgrf.cpp
#	src/newgrf_engine.cpp
#	src/newgrf_railtype.cpp
#	src/newgrf_railtype.h
#	src/newgrf_storage.h
#	src/os/unix/crashlog_unix.cpp
#	src/rail.h
#	src/rail_cmd.cpp
#	src/rail_gui.cpp
#	src/road_cmd.cpp
#	src/road_map.h
#	src/saveload/labelmaps_sl.cpp
#	src/settings_gui.cpp
#	src/settings_type.h
#	src/sl/oldloader_sl.cpp
#	src/station_cmd.cpp
#	src/station_gui.cpp
#	src/table/settings/world_settings.ini
#	src/tests/test_script_admin.cpp
#	src/textfile_gui.cpp
#	src/toolbar_gui.cpp
#	src/train_cmd.cpp
#	src/tunnelbridge_cmd.cpp
#	src/vehicle_gui.cpp
#	src/widget.cpp
#	src/window.cpp
#	src/window_gui.h
#	src/window_type.h

README.md

@@ -399,9 +399,10 @@ The *feature-sx* branches use the savegame framework in the *save_ext* branch.
     - 1.6) [OpenTTD directories](#16-openttd-directories)
     - 1.7) [Compiling OpenTTD](#17-compiling-openttd)
 - 2.0) [Contact and community](#20-contact-and-community)
-    - 2.1) [Contributing to OpenTTD](#21-contributing-to-openttd)
-    - 2.2) [Reporting bugs](#22-reporting-bugs)
-    - 2.3) [Translating](#23-translating)
+    - 2.1) [Multiplayer games](#21-multiplayer-games)
+    - 2.2) [Contributing to OpenTTD](#22-contributing-to-openttd)
+    - 2.3) [Reporting bugs](#23-reporting-bugs)
+    - 2.4) [Translating](#24-translating)
 - 3.0) [Licensing](#30-licensing)
 - 4.0) [Credits](#40-credits)
 
@@ -465,9 +466,9 @@ For some platforms, you will need to refer to [the installation guide](https://w
 The free data files, split into OpenGFX for graphics, OpenSFX for sounds and
 OpenMSX for music can be found at:
 
-- https://www.openttd.org/downloads/opengfx-releases/latest for OpenGFX
-- https://www.openttd.org/downloads/opensfx-releases/latest for OpenSFX
-- https://www.openttd.org/downloads/openmsx-releases/latest for OpenMSX
+- [OpenGFX](https://www.openttd.org/downloads/opengfx-releases/latest)
+- [OpenSFX](https://www.openttd.org/downloads/opensfx-releases/latest)
+- [OpenMSX](https://www.openttd.org/downloads/openmsx-releases/latest)
 
 Please follow the readme of these packages about the installation procedure.
 The Windows installer can optionally download and install these packages.
@@ -532,12 +533,19 @@ If you want to compile OpenTTD from source, instructions can be found in [COMPIL
 - the OpenTTD wiki has a [page listing OpenTTD communities](https://wiki.openttd.org/en/Community/Community) including some in languages other than English
 
 
-### 2.1) Contributing to OpenTTD
+### 2.1) Multiplayer games
+
+You can play OpenTTD with others, either cooperatively or competitively.
+
+See the [multiplayer documentation](./docs/multiplayer.md) for more details.
+
+
+### 2.2) Contributing to OpenTTD
 
 We welcome contributors to OpenTTD.  More information for contributors can be found in [CONTRIBUTING.md](./CONTRIBUTING.md)
 
 
-### 2.2) Reporting bugs
+### 2.3) Reporting bugs
 
 Good bug reports are very helpful.  We have a [guide to reporting bugs](./CONTRIBUTING.md#bug-reports) to help with this.
 
@@ -545,7 +553,7 @@ Desyncs in multiplayer are complex to debug and report (some software developmen
 Instructions can be found in [debugging and reporting desyncs](./docs/debugging_desyncs.md).
 
 
-### 2.3) Translating
+### 2.4) Translating
 
 OpenTTD is translated into many languages.  Translations are added and updated via the [online translation tool](https://translator.openttd.org).