fix: docker installation file path

docker-installation.md

@@ -0,0 +1,35 @@
+**Step 1:** Clone the repo
+
+```
+$ git clone https://github.com/frappe/school.git
+
+$ cd school
+```
+
+**Step 2:** Run docker-compose
+
+```
+$ docker-compose up
+```
+
+**Step 3:** Visit the website at http://localhost:8000/
+
+You'll have to go through the setup wizard to setup the website for the first time you access it. Login using the following credentiasl to complete the setup wizard.
+
+```
+Username: Administrator
+password: admin
+```
+
+TODO: Explain how to load sample data
+
+## Stopping the server
+
+Press `ctrl+c` in the terminal to stop the server. You can also run `docker-compose down` in another terminal to stop it.
+
+To completely reset the instance, do the following:
+
+```
+$ docker-compose down --volumes
+$ docker-compose up
+```