[API docs] line_qubit api format. (quantumlib#5501)

Improves line qubit rendering on api docs.

Author: MichaelBroughton

cirq/devices/line_qubit.py

@@ -44,7 +44,13 @@ def with_dimension(self, dimension: int) -> 'LineQid':
         return LineQid(self.x, dimension)
 
     def is_adjacent(self, other: 'cirq.Qid') -> bool:
-        """Determines if two qubits are adjacent line qubits."""
+        """Determines if two qubits are adjacent line qubits.
+
+        Args:
+            other: `cirq.Qid` to test for adjacency.
+
+        Returns: True iff other and self are adjacent.
+        """
         return isinstance(other, _BaseLineQid) and abs(self.x - other.x) == 1
 
     def neighbors(self, qids: Optional[Iterable[ops.Qid]] = None) -> Set['_BaseLineQid']:
@@ -115,13 +121,14 @@ class LineQid(_BaseLineQid):
     identifies the qids location on the line. `LineQid`s are ordered by
     this integer.
 
-    One can construct new `LineQid`s by adding or subtracting integers:
+    One can construct new `cirq.LineQid`s by adding or subtracting integers:
+
+    >>> cirq.LineQid(1, dimension=2) + 3
+    cirq.LineQid(4, dimension=2)
 
-        >>> cirq.LineQid(1, dimension=2) + 3
-        cirq.LineQid(4, dimension=2)
+    >>> cirq.LineQid(2, dimension=3) - 1
+    cirq.LineQid(1, dimension=3)
 
-        >>> cirq.LineQid(2, dimension=3) - 1
-        cirq.LineQid(1, dimension=3)
     """
 
     def __init__(self, x: int, dimension: int) -> None:
@@ -208,13 +215,14 @@ class LineQubit(_BaseLineQid):
     identifies the qubits location on the line. LineQubits are ordered by
     this integer.
 
-    One can construct new LineQubits by adding or subtracting integers:
+    One can construct new `cirq.LineQubit`s by adding or subtracting integers:
+
+    >>> cirq.LineQubit(1) + 3
+    cirq.LineQubit(4)
 
-        >>> cirq.LineQubit(1) + 3
-        cirq.LineQubit(4)
+    >>> cirq.LineQubit(2) - 1
+    cirq.LineQubit(1)
 
-        >>> cirq.LineQubit(2) - 1
-        cirq.LineQubit(1)
     """
 
     @property