How to make Steam recognise Half-Life 1 HL1 mods liblist.gam

SKIP TO STEP 3 FOR LIBLIST.GAM HELP

key:
Square brackets [] are things you should edit.
Double slash // indicates a comment on the liblist.gam commands.

Step 1) Put the edited folders within a new subfolder in the half life directory. This folder does not need to have the exact name of the mod, and cannot have spaces. i.e. (steamapps\common\Half-Life\[MOD_FOLDER]\maps), etc.

Step 2) If you want an icon for the mod, create a 16x16 TGA file (supported by Paint.NET, GIMP, and Photoshop, among others) and place it in the same directory. (steamapps\common\Half-Life\[MOD_FOLDER]\[OPTIONAL_SUBFOLDER\ICON].tga)

Step 2b) A 32x32 icon would, however, be more desirable, so if you want one, give it the same filename as the small one, but with "_big" appended. (steamapps\common\Half-Life\[MOD_FOLDER]\[OPTIONAL_SUBFOLDER\ICON]_big.tga) Steam will use the larger icon by default.

Step 3) This is the important part. Within your mod directory, create a file named "liblist.gam" and open it with a text editor.
Type these lines into it, complete with quote marks (lines containing "// OPT." are optional, don't copy the comments.):

game "[MOD TITLE]"
developer "[NAME OF DEV/DEVGROUP]"
developer_url "[DEV'S HOMEPAGE URL]"
manual "[MOD INSTRUCTIONS/FAQ URL]" // OPT.
icon "[OPTIONAL_SUBFOLDER\ICON]" // OPT.
gamedll "dlls\hl.dll" // Adds most of the game's functionality on Windows. You can make your own dll for added functionality, but I have no idea how.
gamedll_linux "dlls/hl.so" // Same as above, but for Linux.
gamedll_osx "dlls/hl.dylib" // Same as above, but for Mac.
type "[single]player_only" // OPT. Removes multiplayer game mode. If changed to [multi], removes singleplayer game mode.
startmap "[MAP_NAME]" // OPT. Tells the game which level to load first on singleplayer. File extension not needed.
trainmap "[TUT_MAP]" // OPT. Same as above, but for the training level.
fallback_dir "[OTHER_MOD_FOLDER]" // OPT. If your mod relies on the content of another mod, use this.

For more advanced details (and other commands I didn't figure out), see these two pages on the Valve Dev wiki:
https://developer.valvesoftware.com/wiki/The_liblist.gam_File_Structure
https://developer.valvesoftware.com/wiki/Steam_3rd_Party_Mod_Support#Goldsource
or just Google it.