feat: Improve way to determine and set the path containing the bash config

Before this:
The bash config repo needed to be cloned in ~/.bash/ to work properly

After this:
The bash config repo can be move anywhere (for exemple in
~/.config/bash).
The create-links.bash helper is adapted to this new behaviour.
So you can clone anywhere and call create-links.bash from anywhere. Then
the symbolic links in your home should be good and the config would load
correctly.

bash_profile

@@ -1,12 +1,47 @@
 #!/bin/bash
 
-if [ -f "$HOME"/.nix-profile/etc/profile.d/hm-session-vars.sh ]; then
-	source "$HOME"/.nix-profile/etc/profile.d/hm-session-vars.sh
+if [ -f "${HOME}"/.nix-profile/etc/profile.d/hm-session-vars.sh ]; then
+	source "${HOME}"/.nix-profile/etc/profile.d/hm-session-vars.sh
 fi
 
-if [ -f "$HOME"/.bash/profile ]; then source "$HOME"/.bash/profile; fi
-if [ -d "$HOME"/.bash/profile ]; then for file in "$HOME"/.bash/profile/*; do source "$file"; done; fi
-if [ -d "$HOME"/.bash/profile.d ]; then for file in "$HOME"/.bash/profile.d/*; do source "$file"; done; fi
+# Define the path to the directory of this file if not already set
+if [ -z "${BASH_CONFIG_DIR}" ]; then
+  # Define a function to get the real path of a script
+  # (works for most cases : either sourced script or executed script, posix shells)
+  get_script_dir() {
+    local target
+    # Si appelé depuis un script (Bash), on regarde qui a appelé la fonction (${BASH_SOURCE[1]})
+    # Si la fonction est exécutée directement dans le terminal, on se rabat sur ${BASH_SOURCE[0]} ou ${0}
+    if [ -n "${BASH_SOURCE}" ]; then
+      if [ "${#BASH_SOURCE[@]}" -gt 1 ]; then
+        target="${BASH_SOURCE[1]}"
+      else
+        target="${BASH_SOURCE[0]}"
+      fi
+    elif [ -n "${ZSH_VERSION}" ]; then
+      target="${(%):-%x}"
+    else
+      target="${0}"
+    fi
+
+    # Résolution des liens symboliques POSIX
+    while [ -L "${target}" ]; do
+      local link
+      link=$(readlink "${target}")
+      case "${link}" in
+        /*) target="${link}" ;;
+        *)  target="$(dirname "${target}")/${link}" ;;
+      esac
+    done
+
+    (cd "$(dirname "${target}")" && pwd -P)
+  }
+  BASH_CONFIG_DIR=$(get_script_dir)
+fi
+
+if [ -f "${BASH_CONFIG_DIR}"/profile ]; then source "${BASH_CONFIG_DIR}"/profile; fi
+if [ -d "${BASH_CONFIG_DIR}"/profile ]; then for file in "${BASH_CONFIG_DIR}"/profile/*; do source "$file"; done; fi
+if [ -d "${BASH_CONFIG_DIR}"/profile.d ]; then for file in "${BASH_CONFIG_DIR}"/profile.d/*; do source "$file"; done; fi
 
 # This file is sourced by bash for login shells.  The following line
 # runs your .bashrc and is recommended by the bash info pages.