The highlighter used for github does not handle having unmatched double quotes inside of docstrings/multiline quotes

Eg

```julia

"""
Some docs
An example which is not written correctly
    
   foo("2)
"""
foo(x)=1/2
```


cf: https://github.com/malmaud/TensorFlow.jl/issues/318


vs 


```julia

"""
Some docs
An example which is written correctly
    
   foo("2")
"""
foo(x)=1/2
```