exclude external libs from github statistics (#740)

H-M-H · heinrich5991 · commit 9f2869d2758f · 2017-04-15T00:36:43.000+02:00
for more info consult: https://github.com/github/linguist#using-gitattributes
diff --git a/.gitattributes b/.gitattributes
@@ -0,0 +1,2 @@
+other/*/include/* linguist-vendored
+src/engine/external/* linguist-vendored

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+other//include/ linguist-vendored`
	`2`	`+src/engine/external/* linguist-vendored`