docs: add INSTALL.md to root dir (#9926)

This gives a very quick rundown on installation for end-users (HACKING
etc is for developers/possible contributors).

Signed-off-by: Austin Seipp <austin@well-typed.com>
(cherry picked from commit 9a1c8d96)

INSTALL.md

+Building & Installing
+=====================
+
+For full information on building GHC, see the GHC Building Guide [1].
+Here follows a summary - if you get into trouble, the Building Guide
+has all the answers.
+
+Before building GHC you may need to install some other tools and
+libraries.  See "Setting up your system for building GHC" [2].
+
+NB. in particular you need GHC installed in order to build GHC,
+because the compiler is itself written in Haskell.  For instructions
+on how to port GHC to a new platform, see the Building Guide [1].
+
+For building library documentation, you'll need Haddock [3].  To build
+the compiler documentation, you need a good DocBook XML toolchain and
+dblatex.
+
+Quick start:  the following gives you a default build:
+
+    $ perl boot
+    $ ./configure
+    $ make
+    $ make install
+
+The "perl boot" step is only necessary if this is a tree checked out
+from git.  For source distributions downloaded from GHC's web site,
+this step has already been performed.
+
+These steps give you the default build, which includes everything
+optimised and built in various ways (eg. profiling libs are built).
+It can take a long time.  To customise the build, see the file
+`HACKING.md`.
+
+References
+==========
+
+ [1] http://www.haskell.org/ghc/
+ [2] http://hackage.haskell.org/trac/ghc/wiki/Building/Preparation
+ [3] http://www.haskell.org/haddock/

ghc.mk

@@ -1108,8 +1108,8 @@ SRC_DIST_GHC_DIRS = mk rules docs distrib bindisttest libffi includes \
     utils docs rts compiler ghc driver libraries libffi-tarballs
 SRC_DIST_GHC_FILES += \
     configure.ac config.guess config.sub configure \
-    aclocal.m4 README ANNOUNCE HACKING LICENSE Makefile install-sh \
-    settings.in VERSION GIT_COMMIT_ID \
+    aclocal.m4 README.md ANNOUNCE HACKING.md INSTALL.md LICENSE Makefile
+    install-sh settings.in VERSION GIT_COMMIT_ID \
     boot packages ghc.mk
 
 .PHONY: VERSION