Add notes on versioning of components

docs/changelog/index.njk

@@ -13,6 +13,8 @@ You can [view all releases in the GitHub release log](https://github.com/visual-
 
 Releases of vf-core are done monthly on the last Thursday in each month.
 
+## Versioning
+
 As not all users of the Visual Framework will be able to update to the very latest and we do not wish to hold others back, we are using a [semantic versioning](https://semver.org/) style of releases.
 
 | Major release | Minor release | Note |

docs/guidelines/versioning.njk

+---
+title: Component versioning
+---
+
+[Looking for notes on versioning of vf-core]({{ '/docs/changelog' | path }})?
+
+There are two principles to note:
+
+- Components use a [semantic versioning](https://semver.org/) style of releases
+- Versioning of component is self-contained and distinct from the version number of `vf-core`
+
+That is, if a `vf-pattern@2.2.0` has a breaking change, it would be updated to
+`vf-pattern@v3.0.0` and still be compatible with `vf-core@2.x`.
+
+All patterns should be designed to work with vf-core 2.x, but the may specify a
+minimum required minor version of vf-core.