Update Help Command to display within the application

[ejnan]

Closes #37

[codecov]

Codecov Report

Attention: Patch coverage is 50.00000% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 76.24%. Comparing base (7e024e1) to head (74d7e9f).
Report is 122 commits behind head on master.

❗ Current head 74d7e9f differs from pull request most recent head 3321cf0. Consider uploading reports for the commit 3321cf0 to get more accurate results

Files	Patch %	Lines
src/main/java/seedu/address/ui/MainWindow.java	0.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             master      #53      +/-   ##
============================================
+ Coverage     75.26%   76.24%   +0.98%     
- Complexity      419      431      +12     
============================================
  Files            71       71              
  Lines          1338     1368      +30     
  Branches        126      133       +7     
============================================
+ Hits           1007     1043      +36     
+ Misses          301      288      -13     
- Partials         30       37       +7     

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[ejnan]

Messy branch with new test cases and reverting back to initial commit - created new branch