Fix level setup, reword flow, and catalog scope

- create and enter the level's declared starting directory
- inspect Git state from the repository containing the active directory
- start the init level in /sandbox/git_hug and cover it with a runtime test
- apply edited reword subjects as commit messages in the in-app rebase editor
- cover rename_commit with a native interactive rebase regression test
- remove the upstream contribute call to action from the playable level catalog
- update level parity documentation

app/src/test/java/solutions/tretter/githugandroid/LevelSolutionsTest.kt

@@ -24,8 +24,8 @@ class LevelSolutionsTest {
     }
 
     @Test
-    fun levelOrderMatchesUpstreamRubyGithug() {
-        assertEquals(UPSTREAM_LEVEL_ORDER, allGithugLevels().map { it.id })
+    fun implementedLevelOrderMatchesUpstreamExercises() {
+        assertEquals(IMPLEMENTED_UPSTREAM_LEVEL_ORDER, allGithugLevels().map { it.id })
     }
 
     @Test
@@ -240,7 +240,7 @@ class LevelSolutionsTest {
             return lineSequence().joinToString("\\n", prefix = "\"", postfix = "\"")
         }
 
-        val UPSTREAM_LEVEL_ORDER = listOf(
+        val IMPLEMENTED_UPSTREAM_LEVEL_ORDER = listOf(
             "init",
             "config",
             "add",
@@ -296,7 +296,6 @@ class LevelSolutionsTest {
             "restore",
             "conflict",
             "submodule",
-            "contribute",
         )
 
     }