Null check (#126)
Null check (#126)

* null check doc

Just the design doc for null check

* Revert "null check doc"

This reverts commit e9d3017c3652ffe33a7c6016488a77cca5e53e86.

* Null Check Doc

Just the design doc for null check

* (Draft 2) Renamed file, additional content changes

File is now called Null Checking.md, as per request. Summery of content changes include: 
- grammar/spelling corrections 
- formatting
-correction of erroneous claims about TypeScript

* (Draft 3) Additional Content Changes

-Updated opening paragraph to be informational
-not null -> is not null, as per request
-TypeScript should be actually correct now
-Properties are more fleshed out/better described (hopefully)
-Errata more useful

* Is Null/Is Not Null test files added

* Is Null/Is Not Null command files added

* Revert "(Draft 3) Additional Content Changes"

This reverts commit 17184b84db7ccf3942573ab89303825a1f87324a.

* Revert "Revert "(Draft 3) Additional Content Changes""

This reverts commit 06654981f45246918db1c9551b349bbbe614e612.

* Revert "Is Null/Is Not Null test files added"

This reverts commit 661ca7e241b4c1b785eb5047cb74be11322386a6.

* Revert "Is Null/Is Not Null command files added"

This reverts commit 0c3611eb81e98acfe16c8a42098af8bf93874880.

* Properties Update

-Properties have been properly generalized
-One last formatting change

* Final Commit

-Errata has been updated to better reflect reality

* Properties Update 2

chris-j-tang/GLS,chris-j-tang/GLS,general-language-syntax/GLS,general-language-syntax/GLS,chris-j-tang/GLS,HighSchoolHacking/GLS,HighSchoolHacking/GLS,general-language-syntax/GLS,general-language-syntax/GLS,HighSchoolHacking/GLS,general-language-syntax/GLS,general-language-syntax/GLS,chris-j-tang/GLS,HighSchoolHacking/GLS,HighSchoolHacking/GLS,HighSchoolHacking/GLS,chris-j-tang/GLS,chris-j-tang/GLS