Wes Hardaker explained the reasoning behind why executing that script does not cause it to change the directory of the parent shell. In order to work around that type of issue, you must "souce" the script instead of execute it. This causes the commands in the script to run in the current shell, rather than a child process.
. ./settings.sh
The first "." is a command which tells the shell to "source" the specified file. Here is the documentation from help .:
.: . filename [arguments]
Execute commands from a file in the current shell.
Read and execute commands from FILENAME in the current shell. The
entries in $PATH are used to find the directory containing FILENAME.
If any ARGUMENTS are supplied, they become the positional parameters
when FILENAME is executed.
Exit Status:
Returns the status of the last command executed in FILENAME; fails if
FILENAME cannot be read.
