oCIS C4Model

[mmattel]

As suggested and discussed with @butonic, we are going to use the C4Model to describe the architecture of oCIS in the documentation. The image currently used does not meet the requirements. The C4Model is based on a description file that can be downloaded from the documentation which we will use to generate the necessary svg images. A process is briefly described as comment on top of the file. Because we cant do the work defining the content of that file to describe the architecure, we provided a raw starting point and a first image rendered from that one so you can see where we are. Here is the link to the documentation on staging: https://doc.staging.owncloud.com/ocis/next/architecture/

Our request is, that the oCIS development team refines this file with the details necessary, create a PR in this repo with the update and we will do the imaging on the changes made. Note that you can do this in iterations, but we need to have that ready in only view weeks - means no time to waste...

Info: A C4Model has usually various layers starting from a birds eye view and zooming in. You can use the same file to describe these layers. When you use the linked free website Structurizr DSL to render the file, you can select which layer you want to display and you can see instantly the result from the changes made. Feel free to add additional source files if needed.

You can find the link to the model file we use at:
https://github.com/owncloud/docs-ocis/blob/master/modules/ROOT/attachments/architecture/ocis-c4-model.dsl

@EParzefall fyi