Beatify README.md by means of whitespace.

TBR=nodir@chromium.org

No-Try: True
No-Presubmit: True
Bug: 815072
Change-Id: I653d89f47cd424540c2d4bea3730f8d1d4f37075
Reviewed-on: https://chromium-review.googlesource.com/936184Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>
Commit-Queue: Andrii Shyshkalov <tandrii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#538972}

infra/config/README.md

@@ -2,6 +2,7 @@
 
 There are two kinds of configs: **global** and **ref-specific**.
 
+
 ## Global configs.
 
 Apply to the whole repo regardless of the ref (branch).
@@ -11,6 +12,7 @@ Located in [global](global) directory.
 Currently active version can be checked at
 https://luci-config.appspot.com/#/projects/chromium .
 
+
 ## Ref-specific configs.
 
 Apply only to a ref(branch) they are located in.