guide: roll back accidental removal of HTTP x dep

per #1735 (review)

content/docs/command-reference/config.md

@@ -156,6 +156,15 @@ for more details.) This section contains the following options:
   `dvc remote` for more information on "local remotes".) This will overwrite the
   value provided to `dvc config cache.dir` or `dvc cache dir`.
 
+- `cache.s3` - name of an
+  [Amazon S3 remote to use as external cache](/doc/user-guide/managing-external-data#amazon-s-3).
+
+- `cache.azure` - name of a Microsoft Azure Blob Storage remote to use as
+  [external cache](/doc/user-guide/managing-external-data).
+
+- `cache.gs` - name of a
+  [Google Cloud Storage remote to use as external cache](/doc/user-guide/managing-external-data#google-cloud-storage).
+
 - `cache.ssh` - name of an SSH remote to use
   [as external cache](/doc/user-guide/managing-external-data#ssh).
 
@@ -164,18 +173,9 @@ for more details.) This section contains the following options:
   > hash overlaps: the hash of an external <abbr>output</abbr> could collide
   > with a hash generated locally for another file with different content.
 
-- `cache.s3` - name of an
-  [Amazon S3 remote to use as external cache](/doc/user-guide/managing-external-data#amazon-s-3).
-
-- `cache.gs` - name of a
-  [Google Cloud Storage remote to use as external cache](/doc/user-guide/managing-external-data#google-cloud-storage).
-
 - `cache.hdfs` - name of an
   [HDFS remote to use as external cache](/doc/user-guide/managing-external-data#hdfs).
 
-- `cache.azure` - name of a Microsoft Azure Blob Storage remote to use as
-  [external cache](/doc/user-guide/managing-external-data).
-
 ### state
 
 See

content/docs/user-guide/external-dependencies.md

@@ -22,6 +22,7 @@ supported:
 - Google Cloud Storage
 - SSH
 - HDFS
+- HTTP
 - Local files and directories outside the <abbr>workspace</abbr>
 
 > Note that these are a subset of the remote storage types supported by