added doc/mods

doc/hlmaterials

@@ -51,6 +51,7 @@ sound definitions, we recommend The Wastes method for individual maps, while
 the Nuclide method should be used for Mods or Map Packs. We find these to be
 the most clean and efficient way.
 
-NOTE: We recommend only using materials text files for GoldSrc related modding purposes. It is inefficient for modern projects as there are much better
+NOTE: We recommend only using materials text files for GoldSrc related modding
+purposes. It is inefficient for modern projects as there are much better
 standards already supported in Nuclide. Keep in mind, it takes memory to load
 big text files, and lots of text files adds up over play sessions.

doc/mods

@@ -0,0 +1,42 @@
+Mod loading and setting up games
+================================
+
+For mods to show up in the "Custom Game" menu, we have to either find a manifest
+file, or a liblist.gam, or a gameinfo.txt inside the respective mod directory.
+
+It'll scan .pk3 and .pk4 archives, as well as loose files in the mod directory,
+however it will not search inside any sub-directories.
+It is trying to look inside the dlcache/ folder, but the engine is currently
+restricting that.
+
+A liblist.gam file can look something like this:
+
+game "My Cool Mod"
+version "1.0"
+startmap "e1m1"
+trainingmap "traininglevel"
+
+But more definitions are available.
+Check src/menu-fn/m_customgame.qc's customgame_liblist_parse() function to stay
+up to date regarding all the supported liblist variables that can be set.
+
+GameInfo.txt files are supported too. They originate from the Source Engine
+filesystem, however there's no concept of Tools and Game AppIDs as Nuclide does
+not link against Steamworks.
+Support for such definitions is complementary and I'd advise not to expect it
+to be feature complete. It has a concept of inheriting multiple paths as defined
+by the specification.
+
+If you need more control, you can use manifest files. Similar to the default.fmf
+that's in the root Nuclide source tree. You can set liblist entries like this
+inside of them:
+
+-set gameinfo_game "My Cool Mod"
+-set gameinfo_version "1.0"
+-set gameinfo_startmap "e1m1"
+-set gameinfo_trainingmap "traininglevel"
+
+Please name the manifest the same as the mod/game dir. For example if your game
+its directory is named "foobar" name your manifest "foobar.fmf".
+
+That's all there is to know about mod-detection in Nuclide its menu progs.