Fix github language detection.

Signed-off-by: Tim 'mithro' Ansell <tansell@google.com>

.gitattributes

diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 0000000..9a5ca88
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1,9 @@
+# Settings to improve linguist data reporting (used by GitHub)
+*.v                     linguist-language=Verilog
+*.vh                    linguist-language=Verilog
+*.sql                   linguist-language=SQL
+
+third_party/**          linguist-vendored
+
+# FIXME: All vendor files should be under third_party
+xdc-plugin/tests/minilitex_ddr_arty/**     linguist-vendored