limit indexed string field to 180 char (gotify#184)

Allow markdown in messages (gotify#180)

Add update client api and dialog (gotify#164)

add 386 build targets

Remove -mod=vendor and mount pkg/mod instead

See gotify/plugin-template#4
tl;dr: Using vendor makes plugins incompatible.

Fix build permissions

[gotify#23] Fix check same origin function

Add summary for updateApp and uploadImg api

Add fdroid badge

Fix tslint issues