docs(roles): correct icingaweb2 module descriptions against upstream

* `icingaweb2_module_generictts` README claimed the module rewrites
  ticket patterns in `notes` / `notes_url` fields and listed Jira /
  Redmine / Bugzilla as targets. Both were guesses. Upstream's own
  README says the module operates on acknowledgements, downtimes and
  comments and is generic about the ticket system. Correct the text.
* `icingaweb2_module_fileshipper` README narrowed the Fileshipper's
  Import Source to "host / service definitions". Upstream describes
  it as an Import Source for CSV / JSON / YAML / XML, period (the
  consumer of those imports decides what the data represents).
  Reword.

Author: markuslf

roles/icingaweb2_module_fileshipper/README.md

@@ -1,6 +1,6 @@
 # Ansible Role linuxfabrik.lfops.icingaweb2_module_fileshipper
 
-This role installs and enables the [IcingaWeb2 Fileshipper Module](https://github.com/Icinga/icingaweb2-module-fileshipper). The Fileshipper extends the Icinga Director with the ability to import host / service definitions from CSV / YAML / JSON / XML files on disk and from plain config-file templates.
+This role installs and enables the [IcingaWeb2 Fileshipper Module](https://github.com/Icinga/icingaweb2-module-fileshipper). The Fileshipper extends the Icinga Director with two things: an `Import Source` that reads CSV / JSON / YAML / XML files from disk, and the ability to ship hand-crafted Icinga 2 config files through the Director.
 
 This role is tested with the following IcingaWeb2 Fileshipper Module versions:
 

roles/icingaweb2_module_generictts/README.md

@@ -1,6 +1,6 @@
 # Ansible Role linuxfabrik.lfops.icingaweb2_module_generictts
 
-This role installs and enables the [IcingaWeb2 GenericTTS Module](https://github.com/Icinga/icingaweb2-module-generictts), which renders ticket-system references found in Icinga `notes` / `notes_url` fields as clickable links into a configurable issue tracker (Jira, Redmine, Bugzilla, ...).
+This role installs and enables the [IcingaWeb2 GenericTTS Module](https://github.com/Icinga/icingaweb2-module-generictts). The module rewrites ticket patterns (configurable regular expressions) found in Icinga acknowledgements, downtimes and comments into clickable links pointing at the configured trouble-ticket system.
 
 This role is tested with the following IcingaWeb2 GenericTTS Module versions: