style: add format checker config that matches FRR style standards

Also move .dir-locals.el to a sample file. This file should not be
in the repository as it affects the user's ability to modify it.

Signed-off-by: Christian Hopps <chopps@labn.net>

.flake8

@@ -0,0 +1,3 @@
+[flake8]
+max-line-length = 88
+extend-ignore = E203

.gitignore

@@ -87,6 +87,7 @@
 {arch}
 build
 .cache
+.dir-locals.el
 .msg
 .rebase-*
 *~

.isort.cfg

@@ -0,0 +1,2 @@
+[settings]
+profile = black

.pylintrc

@@ -2,5 +2,8 @@
 init-hook="import sys; sys.path.insert(0, '..')"
 signature-mutators=common_config.retry,retry
 
+[FORMAT]
+max-line-length = 88
+
 [MESSAGES CONTROL]
 disable=I,C,R,W