Add repository toolchain policy

.editorconfig

@@ -0,0 +1,18 @@
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.{c,cpp,cs,h,py,ps1,sh}]
+indent_style = space
+indent_size = 4
+
+[*.{csproj,json,jsonl,props,targets,toml,tscn,tres,xml,yaml,yml}]
+indent_style = space
+indent_size = 2
+
+[*.{bat,cmd}]
+end_of_line = crlf