migrate build scripts from xmonad-testing

The testing repo was not a good location for them, and is now
deprecated. They are now in `scripts/build`, and will be documented
in the main repo's `INSTALL.md`.

scripts/build/build-with-stack.sh

@@ -0,0 +1,23 @@
+#!/bin/sh -eu
+
+################################################################################
+# Edit the following constants and then rename this script to ~/.xmonad/build
+
+# The directory holding your source code and stack.yaml file:
+SRC_DIR=~/develop/oss/xmonad-testing
+
+# The name of the executable produced by stack.  This comes from the
+# executable section of your *.cabal or package.yaml file.
+EXE_NAME=xmonad-testing
+
+################################################################################
+
+# Unset STACK_YAML, to ensure that $SRC_DIR/stack.yaml is used.
+unset STACK_YAML
+
+# Do the build.
+cd $SRC_DIR
+stack build
+
+# Create a hard link at the requested destination, replacing any existing one.
+ln -f -T $(stack exec -- which $EXE_NAME) $1