Fix Comparison Operators and Command Substitution in makestudy Script.

[saksham-gera]

The makestudy Bash script has several issues related to comparison operators and command substitution that can cause errors or compatibility problems. Below are the identified issues and suggested fixes:

1. Equality Operator (== vs =) for Numerical Comparison

2. osascript Check Exit Code Handling ($? Comparison)
   Fix: Use -eq for numerical comparisons.

3. Directory Existence Check in makestudy Script
   issue: The script uses -e to check for directory existence, which detects both files and directories. This can cause conflicts if a file with the same name as the study directory exists, even though it should not prevent study creation.
   Fix: Use -d to specifically check for directories

[saksham-gera]

@pradeeban these are small issues, just let me know if i should fix these in my next PR or not