implement Bash-it#2241

- update `install.sh`
- update `README.md`

Signed-off-by: Max Kovgan <kovganm@gmail.com>

docs/README.md

@@ -46,6 +46,13 @@ That's it! :smiley:
 You can check out more components of Bash-it, and customize it to your desire.  
 For more information, see detailed instructions [here](https://bash-it.readthedocs.io/en/latest/installation/).
 
+### custom configuration file location
+
+By default the instller modifies/creates the actual ``~/.bashrc`` is updated.
+If this is undesirable, you can create another file, by run the installer:
+```bash
+BASH_IT_CONFIG_FILE=path/to/my/custom/location.bash ~/.bash_it/install.sh
+```
 
 ## Contributing
 

install.sh

@@ -194,7 +194,12 @@ case $OSTYPE in
 		;;
 esac
 
+# overriding CONFIG_FILE:
+CONFIG_FILE="${BASH_IT_CONFIG_FILE:-"${CONFIG_FILE}"}"
+# create subdir if CONFIG_FILE has subdirectory components
+[[ "${CONFIG_FILE%/*}" != "${CONFIG_FILE}" ]] && mkdir -p "${CONFIG_FILE%/*}"
 BACKUP_FILE=$CONFIG_FILE.bak
+
 echo "Installing bash-it"
 if [[ -z "${no_modify_config}" ]]; then
 	_bash-it_modify_config_files