Change bashrc file to have daughter scripts

Purpose

This is a very trivial script that modifies the .bashrc script in the current users home directory to search for daughter scripts in the .bashrc.d directory.

It will also create a $HOME/.bashrc.d and $HOME/bin directory to allow the user to add the daughter scripts into the $HOME/.bashrc.d directory, and to add any tools they may wish to include in the $HOME/bin directory.

It is expected that the user will want to add the newly created $HOME/bin directory into the $PATH variable, but this script does not itself do that.

Execution

Simply run the script bash-extend without any arguments, and it will update the .bashrc file and $HOME directory for the currently logged on user.

You may safely run the script many times, since on subsequent execution the script will detect that there is nothing more to be done.