add version command (#123)

* Add /version and /v flags

* Move version info from C Chat.Help to Chat.View

* Move version string, use it in Main startup

* use "SimpleX Chat" consistently

Co-authored-by: TheTaoOfSu <TheTaoOfSu@protonmail.com>

src/Simplex/Chat/Help.hs

@@ -30,7 +30,7 @@ chatHelpInfo :: [StyledString]
 chatHelpInfo =
   map
     styleMarkdown
-    [ highlight "Using SimpleX chat prototype",
+    [ highlight "Using SimpleX Chat",
       "Follow these steps to set up a connection:",
       "",
       green "Step 1: " <> highlight "/connect" <> " - Alice adds a contact.",
@@ -58,6 +58,7 @@ chatHelpInfo =
       indent <> highlight "/profile <name> [<full_name>]" <> " - update user profile",
       indent <> highlight "/delete <contact>" <> " - delete contact and all messages with them",
       indent <> highlight "/markdown        " <> " - show supported markdown syntax",
+      indent <> highlight "/version         " <> " - show SimpleX Chat version",
       indent <> highlight "/quit            " <> " - quit chat",
       "",
       "The commands may be abbreviated to a single letter: " <> listHighlight ["/c", "/f", "/g", "/p", "/h"] <> ", etc."