Instructor scripts (exercises)

Is there any interest in capturing Instructor scripts/exercises that should be simple but convey a concept clearly? Or maybe these could be exercises left to the students?
Such as the following:

### git diff exercise

This exercise will

- (1) show the students that a file may be in 3 local states at the same time and
- (2) will clarify which file (a) or (b) is referred to when git diff shows its output.

#### Setup:
```
$ mkdir show-difs
$ cd show-difs/
$ git init
$ echo "This file is in History" > file.md
$ git add file.md
$ git commit -m "added file.md"
$ echo "This file is in Staged" > file.md
$ git add file.md
$ echo "This file is in Working" > file.md
```
#### Show the results of git diffs

- Show the difference(s) between what's in Working and Staged
- file a is in Staged, file b is in Working
```
$ git diff
diff --git a/file.md b/file.md
index 4959ef4..860e405 100644
--- a/file.md
+++ b/file.md
@@ -1 +1 @@
-This file is in Staged
+This file is in Working
```
- Show the difference(s) between what's in Staged and History
- file a is in History, file b is in Staged
```
$ git diff --staged
diff --git a/file.md b/file.md
index 8ff44ce..4959ef4 100644
--- a/file.md
+++ b/file.md
@@ -1 +1 @@
-This file is in History
+This file is in Staged
```
- Show the difference(s) between what's in Working and History
- file a is in History, file b is in Working
```
$ git diff HEAD
diff --git a/file.md b/file.md
index 8ff44ce..860e405 100644
--- a/file.md
+++ b/file.md
@@ -1 +1 @@
-This file is in History
+This file is in Working
```