Use shorter idiomatic python for README examples (pacifica#24)

Author: dangra

README.md

@@ -18,9 +18,9 @@ The `jsonpath2.path.Path` class represents a JSONPath.
 >>> from jsonpath2.path import Path
 >>> p = Path.parse_str('$["hello"]')
 <jsonpath2.path.Path object>
->>> list(map(lambda match_data: match_data.current_value, p.match(d)))
+>>> [match_data.current_value for match_data in p.match(d)]
 ['Hello, world!']
->>> list(map(lambda match_data: match_data.node.tojsonpath(), p.match(d)))
+>>> [match_data.node.tojsonpath() for match_data in p.match(d)]
 ['$["hello"]']
 ```
 
@@ -130,9 +130,9 @@ The syntax for a function call is the name of the function followed by the argum
 >>> from jsonpath2.path import Path
 >>> p = Path.parse_str('$["hello"][length()]')
 <jsonpath2.path.Path object>
->>> list(map(lambda match_data: match_data.current_value, p.match(d)))
+>>> [m.current_value for m in p.match(d)]
 [13]
->>> list(map(lambda match_data: match_data.node.tojsonpath(), p.match(d)))
+>>> [m.node.tojsonpath() for m in p.match(d)]
 ['$["hello"][length()]']
 ```