Document components design rules

1. A component `make` target MUST NOT, directly or indirectly, depend on _any_ ODK generated files/make targets, in particular not: imports, seeds, merged source files and other components.
2. In the case you do have a _logical_ dependency, you have to manage the dependency yourself by 1) generating the dependency with `make` first and 2) using the generated file in the `make` target of the dependent file (i.e. the component) _without_ having an explicit `make` dependency.

No file or test is named. Start by locating the documentation or build guidance for component make targets, then verify how ODK-generated files and logical dependencies are currently described. Done means the two dependency rules in the issue are documented clearly with the required generation workflow.

Written by the indexing model from the issue text.