Clean up design

[ajrobbins]

Clean up styling of sensor values, headers/subtitles, and "sensors" screen.

[kellyi]

There are currently four states of the text:

• no text shown (which happens for the "Sensor" spoke or if the app fails altogether)
• primary Schuylkill sensor text
• backup Delaware sensor text
• fallback hard-coded values text

The app tries the primary url first, then the secondary url, then uses the fallback values. You can force it to hit the secondary and fallback values by messing with the URL endpoints here:

https://github.com/azavea/pwd-river-dispatches/blob/develop/usgs-details.html#L55

Dropping .usgs from the middle of them works, as it hits an invalid url

[ajrobbins]

Idea for "Sensors" screen:

Here's the Schuylkill sensor's page with the location of the sensor: https://waterdata.usgs.gov/usa/nwis/uv?01474500

I'm thinking we could use a map image with a map pin to indicate where the sensor is in the river, or something.