Fix some PEP8 and minor punctuation mistakes.

Author: aisipos

docs/source/common_issues.rst

@@ -437,7 +437,7 @@ to see the types of all local varaibles at once. Example:
 
    a = 1
    b = 'one'
-   reveal_locals()  # Revealed local types are '{'a': builtins.int, 'b': builtins.str}
+   reveal_locals()  # Revealed local types are '{'a': builtins.int, 'b': builtins.str}'
 
 .. note::
 

mypy/nodes.py

@@ -1599,7 +1599,7 @@ def accept(self, visitor: ExpressionVisitor[T]) -> T:
 
 
 class RevealExpr(Expression):
-    """Reveal type expression reveal_type(expr) or reveal locals expression."""
+    """Reveal type expression reveal_type(expr) or reveal_locals() expression."""
 
     expr = None  # type: Optional[Expression]
     kind = 0  # type: int
@@ -1608,7 +1608,7 @@ class RevealExpr(Expression):
     def __init__(
             self, kind: int,
             expr: Optional[Expression] = None,
-            local_nodes: 'Optional[List[Var]]'=None) -> None:
+            local_nodes: 'Optional[List[Var]]' = None) -> None:
         super().__init__()
         self.expr = expr
         self.kind = kind