move xdg directories to the default location.

a lot of applications seem to hardcode this location, so it's better to
have something default, or default-adjasoned.

.config/clangd/config.yaml

@@ -0,0 +1,22 @@
+---
+CompileFlags:
+  Compiler: gcc
+Index:
+  Background: Build
+  StandardLibrary: true
+Diagnostics:
+  UnusedIncludes: None
+  MissingIncludes: None
+  ClangTidy:
+    FastCheckFilter: Strict
+    Add:
+      - clang-analyzer*
+      - bugprone*
+      - misc*
+      - performance*
+    Remove:
+      - bugprone-narrowing-conversions
+      - bugprone-integer-division
+      - bugprone-implicit-widening-of-multiplication-result
+      - bugprone-switch-missing-default-case
+      - bugprone-easily-swappable-parameters