Move docs from build.py back to README.md

README.md

@@ -1,7 +1,90 @@
+CAUTION: DO NOT FOLLOW EPIC GAMES INSTRUCTIONS
+
+Epic games has a bunch of instructions for installing and building
+Unreal Engine.  Those instructions suck, ignore them completely.
+Instead, we have a script "build.py" that builds Unreal Engine, our
+Game, the Intellisense database, and a bunch of other things as well.
+For building, "build.py" is all you need.
+
+
+SOFTWARE YOU WILL NEED
+
+Before attempting anything, install the following software:
+
+  apt-get install git-lfs
+  apt-get install code
+  apt-get install dotnet6
+  apt-get install clangd-15 or better.
+
+Everything else you need should be included in PopOS.  If that's
+not the case, let me know.
+
+
+GETTING THE CODE
+
+You will need to clone two git repositories:
+
+  cd $HOME
+  git clone https://github.com/EpicGames/UnrealEngine.git
+  git clone https://www.gnaut.com/team/integration.git
+
+The two clone commands above are a simplification.  In reality,
+cloning these two repositories will require you to jump through
+some hoops to get access from Epic Games.  Follow the steps to
+get access from Epic's website, but only go as far as cloning
+the repository.  Once the repository is cloned, we will take it
+from there with our own "build.py".
+
+It is important that these two repositories be located
+at $HOME/UnrealEngine and $HOME/integration.
+
+
+HOW TO BUILD THE FIRST TIME
+
+Change directory into the "integration" repository and run "build.py
+all".  This will build both unreal engine and integration.  It will
+also build project files for vscode, an intellisense database, and
+several other things.  Once it is done, everything is built.
+
+
+HOW TO REBUILD WHEN YOU'VE EDITED SOMETHING
+
+You can also use "build.py all" to rebuild.  This is the preferred
+way to rebuild when you aren't sure what's been edited.  However,
+this takes almost 30 seconds even when there's nothing new to build,
+so it can be a little slow.
+
+If you're sure that the only thing you've edited recently are
+C++ files in the integration repository, then you can get away with
+doing a lightweight build: "build.py c++".  This only works if you've
+already completed a successful full build, and the only thing you've
+done since then is edit C++ files in integration.  If you've edited
+anything else, you need to use "build.py all" to rebuild.
+
+Editing Lua or Blueprint code doesn't require any kind of rebuild.
+
+
+USING VISUAL STUDIO CODE
+
+After building, you can start up the IDE, visual studio code (aka
+vscode).  To start up vscode, change directory to the integration
+repository, and run "code Integration.code-workspace".
+
+The first time you launch vscode, you will see a popup about
+recommended extensions.  These are actually recommended by build.py,
+so they're actually good recommendations.  Install them: you will
+only have to do this once.
+
+From inside vscode, you can use Terminal/Run_Build_Task to execute
+"build.py c++".  If you select Terminal/Run_Task, it will allow you
+to choose between "build.py all", "build.py c++", and "build.py clean".
+This is entirely equivalent to running these commands from the shell.
+
+To launch our game, select Run/Start_Debugging.
+
+
 
-LINUX INSTRUCTIONS:
 
-All the important instructions are in 'build.py'