format readme code blocks

readme.md

@@ -7,11 +7,11 @@ simple URL shortener
 
 - creating a new shortlink at https://pls.cx/shortlink
 
-	susmng [-s pls.cx] create -l shortlink -v https://example.com
+        susmng [-s pls.cx] create -l shortlink -v https://example.com
 
 - deleting the shortlink https://pls.cx/shortlink
 
-	susmng [-s pls.cx] delete -l shortlink -v confirm
+        susmng [-s pls.cx] delete -l shortlink -v confirm
 
 susmng will assume the first server in the 'secrets' section if the -s flag is
 not provided.
@@ -23,11 +23,11 @@ not provided.
 
 1. generate the secret used to create and delete shortlinks
 
-	echo SECRET=`pwgen -s 64 1` >> .env
+        echo SECRET=`pwgen -s 64 1` >> .env
 
 2. run the services
 
-	docker-compose up -d --build
+        docker-compose up -d --build
 
 #### server environment variables
 
@@ -38,10 +38,10 @@ not provided.
 
 1. install susmng
 
-	make install-susmng
+        make install-susmng
 
 2. create config files
 
-	susmng init
+        susmng init
 
-3. edit config files (~/.config/susmng/config.json) to add your secrets
+3. edit config files (`~/.config/susmng/config.json`) to add your secrets