Add an example.

Author: bawr

README.md

@@ -1,2 +1,107 @@
 # gcb
+
 github covert branch
+
+Check out these URLs, then realise they can't be seen from Github navigation.
+https://github.com/bawr/gcb/tree/f178662d86c110746147f1b7afe0ee9f5cda1a69
+https://github.com/bawr/gcb/tree/9bc1b1643e491aa51035a51383af72e8d7eee0f9
+https://github.com/bawr/gcb/tree/refs/remotes/origin/HEAD
+
+```
+alpine:~$ gcb-init bawr gcb gcb-secrets-hidden
+
+Initialized empty Git repository in /home/bawr/gcb-secrets-hidden/.git/
+Switched to a new branch 'master'
+[master (root-commit) e6a0e13] initial covert commit
+
+alpine:~$ cd gcb-secrets-hidden
+
+alpine:~/gcb-secrets-hidden$ gcb-push
+
+Counting objects: 2, done.
+Writing objects: 100% (2/2), 178 bytes | 0 bytes/s, done.
+Total 2 (delta 0), reused 0 (delta 0)
+To https://github.com/bawr/gcb.git
+ * [new branch]      HEAD -> origin/HEAD
+
+alpine:~/gcb-secrets-hidden$ echo secret_one > top-secret.txt
+alpine:~/gcb-secrets-hidden$ git add top-secret.txt
+alpine:~/gcb-secrets-hidden$ git commit -m "Secret one"
+
+[master f3b5817] Secret one
+ 1 file changed, 1 insertion(+)
+ create mode 100644 top-secret.txt
+
+alpine:~/gcb-secrets-hidden$ echo secret_two > top-secret.txt
+alpine:~/gcb-secrets-hidden$ git add top-secret.txt
+alpine:~/gcb-secrets-hidden$ git commit -m "Secret two"
+
+[master f178662] Secret two
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+alpine:~/gcb-secrets-hidden$ gcb-push
+
+Counting objects: 6, done.
+Delta compression using up to 4 threads.
+Compressing objects: 100% (2/2), done.
+Writing objects: 100% (6/6), 501 bytes | 0 bytes/s, done.
+Total 6 (delta 0), reused 0 (delta 0)
+To https://github.com/bawr/gcb.git
+   e6a0e13..f178662  HEAD -> origin/HEAD
+
+alpine:~/gcb-secrets-hidden$ gcb-urls
+
+tree: https://github.com/bawr/gcb/tree/f178662d86c110746147f1b7afe0ee9f5cda1a69
+pack: https://github.com/bawr/gcb/archive/f178662d86c110746147f1b7afe0ee9f5cda1a69.zip
+
+alpine:~/gcb-secrets$ ~/gcb/gcb-clear
+
+To https://github.com/bawr/gcb.git
+ - [deleted]         origin/HEAD
+
+alpine:~/gcb-secrets-hidden$ git ls-remote
+
+From https://github.com/bawr/gcb.git
+8dbfeb09658f4dc780b065bdfe66543f2502b926        HEAD
+8dbfeb09658f4dc780b065bdfe66543f2502b926        refs/heads/master
+```
+
+```
+alpine:~$ gcb-init bawr gcb gcb-secrets-shown
+
+Initialized empty Git repository in /home/bawr/gcb-secrets-shown/.git/
+Switched to a new branch 'master'
+[master (root-commit) 26f3656] initial covert commit
+
+alpine:~$ cd gcb-secrets-shown/
+
+alpine:~/gcb-secrets-shown$ echo top > top-covert.txt
+alpine:~/gcb-secrets-shown$ git add top-covert.txt
+alpine:~/gcb-secrets-shown$ git commit -m "Top covert"
+
+[master 9bc1b16] Top covert
+ 1 file changed, 1 insertion(+)
+ create mode 100644 top-covert.txt
+
+alpine:~/gcb-secrets-shown$ ~/gcb/gcb-push
+
+Counting objects: 5, done.
+Delta compression using up to 4 threads.
+Compressing objects: 100% (2/2), done.
+Writing objects: 100% (5/5), 404 bytes | 0 bytes/s, done.
+Total 5 (delta 0), reused 0 (delta 0)
+To https://github.com/bawr/gcb.git
+ * [new branch]      HEAD -> origin/HEAD
+
+alpine:~/gcb-secrets-shown$ gcb-urls
+
+tree: https://github.com/bawr/gcb/tree/9bc1b1643e491aa51035a51383af72e8d7eee0f9
+pack: https://github.com/bawr/gcb/archive/9bc1b1643e491aa51035a51383af72e8d7eee0f9.zip
+
+alpine:~/gcb-secrets-shown$ git ls-remote
+
+From https://github.com/bawr/gcb.git
+8dbfeb09658f4dc780b065bdfe66543f2502b926        HEAD
+8dbfeb09658f4dc780b065bdfe66543f2502b926        refs/heads/master
+9bc1b1643e491aa51035a51383af72e8d7eee0f9        refs/remotes/origin/HEAD
+```