Add "how to compile jsdoor" for no reason.

src/syncterm/COMPILING

@@ -47,3 +47,6 @@ hdiutil convert ~/Desktop/SyncTERM.dmg -format UDRO -o /Volumes/Synchronet/sbbs/
 
 Release builds for Win32 using MinGW32 use the following command line:
 gmake DONT_CLOBBER_CC=yes CC=mingw32-gcc VERBOSE=please AR=mingw32-ar RANLIB=mingw32-ranlib RELEASE=1 CXX=mingw32-g++ WINDRES=mingw32-windres
+
+Release builds of jsdoor (not related at all)
+gmake jsdoor DONT_CLOBBER_CC=yes CC=mingw32-gcc VERBOSE=please AR=mingw32-ar RANLIB=mingw32-ranlib RELEASE=1 CXX=mingw32-g++ WINDRES=mingw32-windres JSLIBDIR=../../3rdp/win32.release/mozjs/bin/ JSINCLUDE=../../3rdp/win32.release/mozjs/include/ JSLIB=mozjs