Merge pull request #812 from d3i-infra/selfhosting-docs-change

added commas, removed the builtin option

SELFHOSTING.md

@@ -132,7 +132,7 @@ Required environment variables:
 | STATIC_PATH | Path to folder where uploaded files can be stored | "/tmp" |
 | UNSPLASH_ACCESS_KEY | Application access key registered on [Unsplash](https://unsplash.com/) (Image Catalog) | "hcejpnHRuFWL-fKXLYqhGBt1Dz0_tTjeNifgD01VkGE" |
 | UNSPLASH_APP_NAME | Application name registered on [Unsplash](https://unsplash.com/) (Image Catalog) | "Self" |
-| STORAGE_SERVICES | Comma seperated list of storage services | "builtin yoda aws azure" |
+| STORAGE_SERVICES | Comma seperated list of storage services | "yoda, aws, azure" |
 
 Optional environment variables:
 
@@ -150,4 +150,4 @@ Optional environment variables:
 | FELDSPAR_S3_PREFIX | Prefix for S3 feldspar objects | "feldspar" |
 | PUBLIC_S3_URL | Public accessable url of an S3 service | "https://self-public.s3.eu-central-1.amazonaws.com" |
 | PUBLIC_S3_BUCKET | Name of the bucket on the S3 service | "self-prod" |
-| DIST_HOSTS | Comma seperated list of hosts in the cluster, see: [OTP Distribution](https://elixirschool.com/en/lessons/advanced/otp_distribution) | "one, two" |
+| DIST_HOSTS | Comma seperated list of hosts in the cluster, see: [OTP Distribution](https://elixirschool.com/en/lessons/advanced/otp_distribution) | "one, two" |