Handle search query without a space between dept and course #

Searching for "cs1331" should return the same results as "cs 1331". This preg_replace adds the space if it matches the former format. 

Test of the regex:
```php
 $queries = array(
     'c',
     'cs',
     'cs1',
     'cs123',
     'cs 123',
     'csasfsafas',
     'math',
     'loss',
     'loss michael',
 );
 
 $regex = '/^([A-Za-z]*)(\d*)$/';
 $replacement = '$1 $2';
 
 foreach ($queries as $query) {
     echo $query . ' -> ' . preg_replace($regex, $replacement, $query) . "\n";
 }
```
Output:
```
$ php fuzzy.php 
c -> c 
cs -> cs 
cs1 -> cs 1
cs123 -> cs 123
cs 123 -> cs 123
csasfsafas -> csasfsafas 
math -> math 
loss -> loss 
loss michael -> loss michael
```