build: add .gitignore files to some 3rd party libraries

vor 8 Jahren · e8cb6606ac
--- a/src/3rdparty/bullet3
+++ b/src/3rdparty/bullet3
@@ -1 +1 @@
 Subproject commit 069669c9c2efee4facc2c69490df0238f72eaee3
 Subproject commit 8c6a20ecbeede5dfa8ae34355a82a4097d0cacbd
--- a/src/3rdparty/lua
+++ b/src/3rdparty/lua
@@ -1 +1 @@
 Subproject commit 901bbc987451a6c55a329779066998f0a2c382bf
 Subproject commit c43cfa79e9f4d065be03e2e612f73c329aea972a