Uploading docs and saving signed docs to storage

[alexeyvolkoff]

Hi @AlexandrToorchyn!
First of all, great job 👍 The best self-hosted eSignature solution so far.
The couple of things to ask before I go into docker:

• Is it possible to upload the document (template?) via API or import it from the storage?
• Is it possible to save the signed document to custom https/webdav storage automatically?

And yes, someone mentioned 'Template' is a little bit confusing term, maybe 'Deal' is better? In the main screen, they may be listed under 'Recent deals' or just 'Recent', some of them may have 'repeatable' check. Just an idea. Though internally in API 'template' is correct term.