[meld/precommit] Add isort to pre-commit config

[Kai Willadsen <kaiw src gnome org>]

commit f072407a8a1e6526a83f82225973048a4c4c569a
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Sun Oct 6 08:45:04 2019 +1000

    Add isort to pre-commit config
    
    We were already running isort through flake8, but adding this plugin
    means we also get automatic sorting on pre-commit runs.

 .pre-commit-config.yaml | 6 ++++++
 1 file changed, 6 insertions(+)
---
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index f42e6030..be45a6f3 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -22,6 +22,12 @@ repos:
         args: [--no-sort-keys, --indent=2]
     -   id: trailing-whitespace
 
+-   repo: https://github.com/timothycrosley/isort
+    rev: 4.3.21-2
+    hooks:
+    -   id: isort
+        args: [--filter-files]
+
 -   repo: https://gitlab.com/pycqa/flake8
     rev: 3.7.5
     hooks: