reorganizing configuration

- static package configuration in `vars/pkgs`
  - loaded into the variable `pkgconfig` as part of `tasks/main.yml`

vars/pkgs/alacritty.yml

@@ -0,0 +1,25 @@
+alacritty:
+  version: 0.15.0
+  RedHat:
+    pkgs: []
+    build_deps:
+      - cmake
+      - freetype-devel
+      - fontconfig-devel
+      - libxcb-devel
+      - libxkbcommon-devel
+      - g++
+  Debian:
+    pkgs: []
+    build_deps:
+      - cmake
+      - pkg-config
+      - libfreetype6-dev
+      - libfontconfig1-dev
+      - libxcb-xfixes0-dev
+      - libxkbcommon-dev
+      - python3
+  Darwin:
+    pkgs:
+      - alacritty
+  git_repo: https://github.com/alacritty/alacritty.git