Added python method with default arguments definition
Added ruby non-interpolated string info
Added multi-line strings with java example
Added python multiple-line spanning literals
Fixed typo
Added more on Python string literals
Added lots of references and clarifications for python integer literals
Added python escaping quotes in strings
Added escaping newlines
Added strings immutability
Added longer description of 01-data-types/10-list/21-allows-extra-separator-at-the-end
Added Python string immutability
More string operations: length & concat
Moved string operations from stdlib to the single place at datatypes
Added more python string operations