add script: build minetest from current directory

build-minetest-here.sh

@@ -0,0 +1,5 @@
+#!/bin/bash
+if [ -f bin/minetest ]; then
+    make clean
+fi
+cmake . -DENABLE_GETTEXT=1 -DENABLE_FREETYPE=1 -DENABLE_LEVELDB=1 -DENABLE_REDIS=1 -DRUN_IN_PLACE=1 && make -j$(grep -c processor /proc/cpuinfo)