a little more on text geometry interaction

docs/components/text.md

@@ -159,13 +159,39 @@ or the text can auto-scale the geometry to fit the text.
 [geometryimg]: https://cloud.githubusercontent.com/assets/674727/22358470/218689d6-e3f4-11e6-9e00-62c9cb7867da.png
 ![Geometry Alignments][geometryimg]
 
-To have the geometry automatically scale with the text, set the geometry
-component's `width` and `height` properties to `auto`:
+To have the text component's `width` property automatically scale
+to match the geometry component's `width`, do not specify a `width`
+for the text component:
 
 ```html
-<a-entity
+<a-entity position="0 1 -2"
+  geometry="primitive: plane; width: 4; height: auto"
+  material="color: blue"
+  text="value: This text will be 4 units wide."></a-entity>
+```
+
+To have the geometry automatically scale with the text,
+set the geometry component's `width` and `height` properties to `auto`,
+and set the text component's `width` as desired.
+In this example, the plane's `width` will be set to 4 units,
+and its `height` will be set to match the actual height of the text:
+
+```html
+<a-entity position="0 1 -2"
   geometry="primitive: plane; height: auto; width: auto"
-  text="value: Auto scale!"></a-entity>
+  material="color: blue"
+  text="width: 4; value: This text will be 4 units wide."></a-entity>
+```
+
+Note that if neither `geometry` nor `text` specify a width,
+the text `width` property will default to 1 unit (meter),
+and the geometry `width` property will then become 1 unit as well.
+
+```html
+<a-entity position="0 1 -2"
+  geometry="primitive: plane"
+  material="color: blue"
+  text="value: 1-wide\ndefault."></a-entity>
 ```
 
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