add docs for component

Author: bdlb77

docs/components/meter.md

@@ -0,0 +1,60 @@
+# matestack core component: Main
+
+Show [specs](/spec/usage/components/meter_spec.rb)
+
+Use the Meter component to implement `<meter>` tag.
+
+## Parameters
+
+#### # value (required)
+Expects a number thats is the current value of the gauge.
+
+#### # id (optional)
+Expects a string with all ids the main should have.
+
+#### # class (optional)
+Expects a string with all classes the main should have.
+
+#### # min (optional)
+Expects a number that defines the minimum value of the range.
+
+#### # max (optional)
+Expects a number that defines the maximum value of the range.
+
+#### # low (optional)
+Expects a number that defines which value is considered a low value
+
+#### # high (optional)
+Expects a number that defines which value is considered a high value
+
+#### # optimum (optional)
+Expects a number that defines which value is optimal for the gauge
+
+
+
+
+## Example
+
+```ruby
+meter id: 'meter_id', value: 0.6
+
+meter id: 'meter', min: 0, max: 10, value: 6 do
+	plain '6 out of 10. 60%.'
+end
+
+meter id: 'meter', low: 2, high: 8, optimum: 6, min: 0, max: 10, value: 6 do
+	plain '6 out of 10. 60%.'
+end
+```
+
+returns
+
+```html
+<meter id="meter_id" value="0.6"></meter>
+      
+<meter id="meter" max="10" min="0" value="6">6 out of 10. 60%.</meter>
+
+<meter high="8" id="meter" low="2" max="10" min="0" optimum="6" value="6">
+	6 out of 10. 60%.
+</meter>
+```