[Julia] Update README checklist (#331)

Author: SaschaMann

languages/julia/README.md

@@ -13,7 +13,7 @@ This area will contain everything needed to launch the Julia track, including:
 Before we publicize requesting contribution for this language, the following steps should be done.
 
 - [x] [Convert existing files to new repository structure](../../docs/maintainers/repository-structure.md)
-- [ ] Have a kick-off discussion between track maintainers
+- [x] Have a kick-off discussion between track maintainers
 - [x] Fill out the [maintainers.md](./maintainers.md) file (e.g. [C#](../csharp/maintainers.md))
 - [x] Ensure there is a link to your track's GitHub issues on the [main README.md](../../README.md)
 - [ ] [Write a Concept Exercise implementation guide](../../docs/maintainers/writing-a-concept-exercise-github-issue.md)
@@ -28,10 +28,10 @@ Before launch, we need all of the following parts to be completed:
 
 - [ ] Implemented 20+ Concept Exercises
 - [ ] [Updated `config.json`](../../docs/maintainers/migrating-your-config-json-files.md)
-  - [ ] Added `version` key
-  - [ ] Added online editor settings
-    - [ ] Added `indent_style`
-    - [ ] Added `indent_size`
+  - [x] Added `version` key
+  - [x] Added online editor settings
+    - [x] Added `indent_style`
+    - [x] Added `indent_size`
   - [ ] Added Concept Exercises
   - [ ] Added Concepts for all Practice Exercises