Merge pull request #125 from r-gaia-cs/update-layout

    > * Learning objective 1

    > * Learning objective 2

    Paragraphs of text --- possibly including **definitions** ---

    Paragraphs of text

    --- possibly including [definitions](reference.html#definitions) ---

    mixed with:

    ~~~ {.python}

3.  Every challenge should relate explicitly back to a learning

    objective.

4.  Definitions of terms are marked in **bold** (like `**this**`).

    Nothing else should be marked as bold text --- use *italics* for

    for all other emphasis.

4.  Definitions are links with fragment identifier to `reference.html`

    (like `[definitions](reference.html#definitions)`).

    This is need to enable links from name diferent from the key word defined.

5.  When laying out source code, use `{.lang}` as a style on the

    opening `~~~` line.  For Unix Shell commands use:

    ## Glossary

    Key Word 1

    key word 1

    :   Definition of first term

    Key Word 2

    key word 2

    :   Definition of second term

## Discussion Page