Change environment variable to .env file, to prevent the change of docker-compose file

.env.example

@@ -0,0 +1,3 @@
+REPOSITORY_LOCATION=
+CONFIG_LOCATION=
+TIMEZONE=

README.md

@@ -10,13 +10,13 @@ Clone this repository
 Enter the repository and run `npm install`. This will install all the required dependencies.
 
 ## Step 3
-Edit the `docker-compose.yml` file.
+Make a copy from `.env.example` file and rename it `.env`.
 
-Replace `<your-repository-location>` with the full path to your repository.
+Add the full path of your repository on the `REPOSITORY_LOCATION` variable.
 
-Replace `<your-config-location>` with the directory in which you would like to store your configuration.
+Add the directory in which you would like to store your configuration on the `CONFIG_LOCATION` variable.
 
-Replace `<your-timezone>` with your timezone.
+Add your timezone on the `TIMEZONE` variable
 
 ## Step 4
 Run the command `docker build -t librarian .` and then `docker-compose up -d`

docker-compose.yml

@@ -7,8 +7,8 @@ services:
     command: >
       node index.js
     volumes:
-      - <your-repository-location>:/usr/src/bot
-      - <your-config-location>:/.store
+      - ${REPOSITORY_LOCATION}:/usr/src/bot
+      - ${CONFIG_LOCATION}:/.store
     environment:
-      - TZ=<your-timezone>
+      - TZ=${TIMEZONE}
     restart: unless-stopped