Added geometry formula shower / calculator Goodie

**What does your instant answer do?**
This goodie shows geometric formulas (e.g. circle area) or calculates them if sizes are specified.

**What is the data source for your instant answer? (Provide a link if possible)**
The german "Tafelwerk", because it is a good formulary

**What are some example queries that trigger this instant answer?**
formula circle area
for more: see test file

**Is this instant answer connected to a DuckDuckHack [instant answer idea](https://duck.co/ideas)?**
Yes, https://duck.co/ideas/idea/1053/geometry-calculator.

**Which existing instant answers will this one supercede/overlap with?**
Not known yet

**Are you having any problems? Do you need our help with anything?**
Not yet

- [x] Added metadata and attribution information
- [x] Wrote test file and added to t/ directory
- [x] Verified that instant answer adheres to design guidelines(https://github.com/duckduckgo/duckduckgo-documentation/blob/master/duckduckhack/styleguides/design_styleguide.md)
- [x] Tested cross-browser compatability *with support tables*; in brackets the feature which is used and has the lowest support for this browser
 - IE from version 9 (SVG)
 - Firefox from version 6 (data-*)
 - Chrome from version 7 (data-*)
 - Safari from version 5 (data-*)
 - Opera from version 11 (data-*)
- [x] Tested live only on Linux 64-bit, Firefox
I agree with @moollaza here.  You've got everything in a hash structure above, but you're not really deriving the benefit therefrom.  In my experience, the best strategy is to put a human-friendly structure into the source.. along with some code to translate it into something more machine-friendly.

So each "shape" key might point to a hashref which contains an array-ref of aliases, a scalar SVG definition, plus a hash-ref of formulae.  Then, at start up you can go through and rearrange the structure such that each alias actually points to the original reference.  You might also extract all of the available (shape? and) formulae names into regexes to make it easier to spot and extract them from the query. No (well, nominal) extra space, easier to maintain and much less computationally expensive at request time.

Of course for this to work well, you need to do a bit of cleaning and normalization on the incoming query to find the particular pieces you need.

I just noticed a message which suggested a move to `Spice` so maybe I should just stop here.