Add documentation for ternary operation messages (#7970)

Co-authored-by: Pierre Sassoulas <[email protected]>

Author: zenlyj

doc/data/messages/c/consider-ternary-expression/bad.py

@@ -0,0 +1,5 @@
+x, y = input(), input()
+if x >= y:  # [consider-ternary-expression]
+    maximum = x
+else:
+    maximum = y

doc/data/messages/c/consider-ternary-expression/details.rst

@@ -1 +1,2 @@
-# This is a placeholder for correct code for this message.
+x, y = input(), input()
+maximum = x if x >= y else y

doc/data/messages/c/consider-ternary-expression/good.py

@@ -0,0 +1,2 @@
+[MAIN]
+load-plugins=pylint.extensions.consider_ternary_expression

doc/data/messages/c/consider-ternary-expression/pylintrc

@@ -0,0 +1,2 @@
+x, y = 1, 2
+maximum = x >= y and x or y  # [consider-using-ternary]

doc/data/messages/c/consider-using-ternary/bad.py

@@ -1 +1,2 @@
-# This is a placeholder for correct code for this message.
+x, y = 1, 2
+maximum = x if x >= y else y