Docs for Official Repo release

Changes and additions for the Official Repo release on Wednesday.
```
    RUN mdkir -p /usr/src/things \
        && curl -SL http://example.com/big.tar.gz \
        | tar -xJC /usr/src/things \
        && make -C /usr/src/things all
```

mmm, most times I see this code written as

```
    RUN mdkir -p /usr/src/things && \
        curl -SL http://example.com/big.tar.gz | tar -xJC /usr/src/things && \
        make -C /usr/src/things all
```

putting the `|` on a separate line seems to me to obscure that its one operation - and the `&&` at the beginning, is probably irrelevant.