fix(has-city): remove backslash that causes unexpected markdown render behaviour

subjects/has-city/README.md

@@ -2,7 +2,7 @@
 
 ### Instructions
 
-Create a function `hasCity` that takes a string called `country` and an array of strings, which are cities of that country, which returns a new function. \
+Create a function `hasCity` that takes a string called `country` and an array of strings, which are cities of that country, which returns a new function.
 The new function takes a string, called `city`, as a parameter and which determines
 whether the array contains that string or not.