Started adding content authoring details to the readme. Added information on...

Started adding content authoring details to the readme. Added information on the Blockdown format for the Ethical Design Violations section (trackers badge).

readme.md

@@ -16,7 +16,7 @@ This content is processed by [Better Builder](https://source.ind.ie/better/build
 
 A seminal advantage of Better is that its database is human-readable, open, and extensible via pull requests. (The database is curated by Ind.ie using the Ethical Design Manifesto as the criteria for blocking rules.)
 
-Contributing to the content is as easy as creating an account on [source.ind.ie](https://source.ind.ie) and editing a content page in your browser.s
+Contributing to the content is as easy as creating an account on [source.ind.ie](https://source.ind.ie) and editing a content page in your browser.
 
 ## I’m not a developer, I just want to experience a Better web.
 
@@ -28,4 +28,49 @@ Buying Better on the App Store is one way to support us. If you want to help wit
 
 ## I’m a developer, let me in!
 
-The easiest way to get started is to follow the instructions in the readme for the [Better iOS app](https://source.ind.ie/better/app) repository.
\ No newline at end of file
+The easiest way to get started is to follow the instructions in the readme for the [Better iOS app](https://source.ind.ie/better/app) repository.
+
+## Guide to Blockdown
+
+Blockdown is Markdown with an extended high-level vocabulary for describing web malware for the Better database.
+
+### Sites
+
+Site pages have the following sections:
+
+#### Ethical design violations
+
+```markdown
+## Ethical design violations
+```
+
+This is a list of ethical design violations that gets converted to a collection of badges on the rendered site pages.
+
+The first badge is always the trackers badge. In Blockdown it is represented by a list item introduced by the word `Trackers`:
+
+```markdown
+  * Trackers (exposes you to NNN third-party sites)
+```
+
+We get the statistic for the number of third-party sites that a person browsing the site is exposed to by using [Mozilla Lightbeam](https://www.mozilla.org/en-US/lightbeam/).
+
+Following the badge heading list item, there is a sublist of site URLs. For example, here’s an excerpt from the [cultofmac.com site page](https://better.fyi/sites/cultofmac.com):
+
+```markdown
+* Trackers (exposes you to 155 third-party sites)
+  * w.soundcloud.com
+  * goroost.com
+  * taboola.com
+  * google-syndication.com
+  * …
+```
+
+This gets automatically translated by [Better Builder](https://source.ind.ie/better/builder) to a badge similar to the one below:
+
+![Screenshot of the trackers badge](images/readme/blockdown-trackers-badge-example.png)
+
+Specifically, the builder counts the number of trackers for you and juxtapositions that with the number of third-party sites that you entered manually.
+
+Tapping on the badge displays a popover with links to the actual trackers.
+
+![Screenshot of the trackers popover](images/readme/blockdown-trackers-popover-example.png)