Add basic documentation on how the lib works

1 files changed, 47 insertions, 0 deletions

diff --git a/doc/src/05100-lib-contacts.md b/doc/src/05100-lib-contacts.md
index 4bdd5371..25e69069 100644
--- a/doc/src/05100-lib-contacts.md
+++ b/doc/src/05100-lib-contacts.md
@@ -1,2 +1,49 @@
 ## libimagcontacts
 
+The contact library basically only creates references to the actual icalendar
+and vcard files, though it also can parse (via the `vobject` crate) the
+information and return it from an entry directly.
+
+The architecture of indirections is as follows:
+
+```{.numberLines}
+
++--------------------------------+
+|                                |
+|     Store, as ContactStore     |
+|                                |
++----------------+---------------+
+                 |
+                 | Provides access to
+                 |
++----------------v---------------+
+|                                |
+|   (FileLock)Entry as Contact   |
+|                                |
+|      which is actually a:      |
+|                                |
+|     (FileLock)Entry as Ref     |
+|                                |
++----------------+---------------+
+                 |
+                 | refers to
+                 |
++----------------v---------------+
+|                                |
+|   vcard file (outside store)   |
+|                                |
++----------------+---------------+
+                 |
+                 | contains
+                 |
++----------------v---------------+
+|                                |
+|            vcard data          |
+|                                |
++--------------------------------+
+
+```
+
+As the library is build upon `libimagentryref`, it does not create a new
+subcollection in the store `/contacts`, but uses the infrastructure of
+`libimagentryref` which automatically puts all references in `/ref`.