Update changelog and documentation

CHANGELOG.md

@@ -1,3 +1,13 @@
+# 2020-03-15
+
+## Raspberry Pi support
+
+The playbook supports installing to a Raspberry Pi server, for at least some of the services.
+
+Since most ready-made container images do not support that architecture, we achieve this by building images locally on the device itself.
+See our [Self-building documentation page](docs/self-building.md) for how to get started.
+
+
 # 2020-02-26
 
 ## Riot-web themes are here

docs/self-building.md

@@ -1,6 +1,6 @@
-# Self building
+# Self-building
 
-The playbook supports the self building of a couple of components. This may be useful for architectures beside x86_64 that have no docker images right now (e g. the armv7 for the Raspberry Pi). Some roles have been updated, so they build the necessary image on the host. It needs more space, as some build tools need to be present (like Java, for mxisd).
+The playbook supports the self-building of some of its components. This may be useful for architectures besides x86_64, which have no Docker images right now (e g. the armv7 for the Raspberry Pi). Some playbook roles have been updated, so they build the necessary image on the host. It needs more space, as some build tools need to be present (like Java, for mxisd).
 
 To use these modification there is a variable that needs to be switched to enable this functionality. Add this to your `vars.yaml` file:
 ```yaml
@@ -15,3 +15,5 @@ List of roles where self-building the docker image is currently possible:
 - mxisd
 - matrix-bridge-mautrix-facebook
 - matrix-bridge-mautrix-hangouts
+
+Adding self-building support to other roles is welcome. Feel free to contribute!