Edited string methods (#186)

* Changed numeric check regex
- `^` may match the position right after a newline character, and `$` may match right before the newline character (due to the multiline flag being enabled by default), so substing these with `\A` and `\Z`.
- Changed both instances of `[0-9]` with the shorthand `\d`.
- Removed capturing group around the first `\d+`.
* Changed get character at index
`anyString[0, 1]` is functionally the same as `anyString[0]` because the range `[a, b]` returns all characters from index `a` up to but not including the char at index `b`.

Data/Scripts/001_Technical/002_RubyUtilities.rb

@@ -23,7 +23,7 @@ end
 #===============================================================================
 class String
   def starts_with_vowel?
-    return ["a", "e", "i", "o", "u"].include?(self[0, 1].downcase)
+    return ["a", "e", "i", "o", "u"].include?(self[0].downcase)
   end
 
   def first(n = 1); return self[0...n]; end
@@ -52,7 +52,7 @@ class String
   end
 
   def numeric?
-    return !self[/^[+-]?([0-9]+)(?:\.[0-9]+)?$/].nil?
+    return !self[/\A[+-]?\d+(?:\.\d+)?\Z/].nil?
   end
 end