Added try-except-raise message example

doc/data/messages/t/try-except-raise/bad.py

@@ -0,0 +1,4 @@
+try:
+    1 / 0
+except ZeroDivisionError as e:  # [try-except-raise]
+    raise

doc/data/messages/t/try-except-raise/details.rst

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+There is a legitimate use case for re-raising immediately. E.g. with the following inheritance tree::
+
+    +-- ArithmeticError
+         +-- FloatingPointError
+         +-- OverflowError
+         +-- ZeroDivisionError
+
+The following code shows valid case for re-raising exception immediately::
+
+    def execute_calculation(a, b):
+        try:
+            return some_calculation(a, b)
+        except ZeroDivisionError:
+            raise
+        except ArithmeticError:
+            return float('nan')
+
+The pylint is able to detect this case and does not produce error.

doc/data/messages/t/try-except-raise/good.py

@@ -0,0 +1,8 @@
+# The try except might be removed entirely:
+1 / 0
+
+# Or another more detailed exception can be raised:
+try:
+    1 / 0
+except ZeroDivisionError as e:
+    raise ValueError("The area of the rectangle cannot be zero") from e