Add doc8 documentation style checking

- add dev dependency
- add doc8 to tasks.py
- fix all doc8 errors

1 files changed, 9 insertions, 8 deletions

diff --git a/docs/migrating/incompatibilities.rst b/docs/migrating/incompatibilities.rst
index 3d7ddcfb..7a8a5aba 100644
--- a/docs/migrating/incompatibilities.rst
+++ b/docs/migrating/incompatibilities.rst
@@ -3,8 +3,8 @@ Incompatibilities
 
 .. _cmd: https://docs.python.org/3/library/cmd.html
 
-``cmd2`` strives to be drop-in compatible with cmd_, however there are a few things
-that are not.
+``cmd2`` strives to be drop-in compatible with cmd_, however there are a few
+things that are not.
 
 
 cmd.emptyline()
@@ -13,9 +13,10 @@ cmd.emptyline()
 The `cmd.emptyline()
 <https://docs.python.org/3/library/cmd.html#cmd.Cmd.emptyline>`_ function is
 called when an empty line is entered in response to the prompt. By default, in
-cmd_ if this method is not overridden, it repeats and executes the last nonempty
-command entered.  However, no end user we have encountered views this as
-expected or desirable default behavior.  Thus, the default behavior in ``cmd2``
-is to simply go to the next line and issue the prompt again.  At this time, cmd2
-completely ignores empty lines and the base class cmd.emptyline() method never
-gets called and thus the emptyline() behavior cannot be overridden.
+cmd_ if this method is not overridden, it repeats and executes the last
+nonempty command entered.  However, no end user we have encountered views this
+as expected or desirable default behavior.  Thus, the default behavior in
+``cmd2`` is to simply go to the next line and issue the prompt again.  At this
+time, cmd2 completely ignores empty lines and the base class cmd.emptyline()
+method never gets called and thus the emptyline() behavior cannot be
+overridden.