[zsh] Implement loading of custom scripts.

zsh/.gitignore

@@ -0,0 +1 @@
+custom

zsh/zshrc

@@ -1,11 +1,15 @@
 #!/usr/bin/env zsh
 
-K_ZSH_DOTFILES="${0:h}"
-
 # Get this file's current directory and source Dima's zshrc from there
-SCRIPT_DIR="$( dirname "$( readlink -f "$0" )" )"
-source $SCRIPT_DIR/../dmitmel-dotfiles/zsh/zshrc
+K_ZSH_DOTFILES="$( dirname "$( readlink -f "$0" )" )"
+source $K_ZSH_DOTFILES/../dmitmel-dotfiles/zsh/zshrc
 
 for script in functions; do
   source "$K_ZSH_DOTFILES/$script.zsh"
 done
+
+if [[ -d "$K_ZSH_DOTFILES/custom" ]]; then
+  for script in $K_ZSH_DOTFILES/custom/*.zsh; do
+    source "$script"
+  done
+fi