README.md: Indent sub-lists with two spaces

Signed-off-by: Uli Schlachter <psychon@znc.in>

README.md

@@ -55,12 +55,12 @@ section in `recipes.mdwn` file.
 1. Create a new page with your tutorial/setup/widget/snippet in Markdown, with a
    relevant name, under the `recipes` folder.
 
-   - Example `recipes/xrandr-tutorial.mdmw`
+  - Example `recipes/xrandr-tutorial.mdmw`
 
 1. Link your page to the right section in the `recipes.mdwn` page with Markdown
    syntax.
 
-   - Example `[XrandR Tutorial](../recipes/xrandr-tutorial.html)`
+  - Example `[XrandR Tutorial](../recipes/xrandr-tutorial.html)`
 
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