Fix table of contents README links

Signed-off-by: Juan Cruz Viotti <jv@jviotti.com>

Author: jviotti

README.markdown

@@ -33,10 +33,10 @@ designing great APIs.*
 
 - [:blue_book: Standards](#blue_book-standards)
 - [:rocket: Getting Started](#rocket-getting-started)
-      - [From Sourcemeta Schemas](#from-sourcemeta-schemas)
-      - [From GitHub Releases](#from-github-releases)
-      - [Using Git Submodules](#using-git-submodules)
-      - [Using Vendorpull](#using-vendorpull)
+    - [From Sourcemeta Schemas](#from-sourcemeta-schemas)
+    - [From GitHub Releases](#from-github-releases)
+    - [Using Git Submodules](#using-git-submodules)
+    - [Using Vendorpull](#using-vendorpull)
 - [:page_facing_up: License](#page_facing_up-license)
 - [:handshake: Contributing](#handshake-contributing)
 - [:email: Contact](#email-contact)