tweak formatting to make easier to copy the list

Author: freyfogle

category_values.md

@@ -1,22 +1,24 @@
 List of possible `_category` values in the `components` portion of a geocoding result. Please see [the OpenCage Geocoder API docs](https://opencagedata.com/api#formatted) for details.
 
-  * agriculture
-  * building
-  * commerce
-  * construction
-  * education
-  * financial
-  * government
-  * health
-  * industrial
-  * military
-  * natural/water
-  * outdoors/recreation
-  * place
-  * place_of_worship
-  * postcode
-  * road
-  * social
-  * transportation
-  * travel/tourism
-  * unknown
+```
+agriculture
+building
+commerce
+construction
+education
+financial
+government
+health
+industrial
+military
+natural/water
+outdoors/recreation
+place
+place_of_worship
+postcode
+road
+social
+transportation
+travel/tourism
+unknown
+```