Dev guide: mention field types for manifest, along with examples edit…

…ed to show proper value format. Re nvaccess#8593

developerGuide.t2t

@@ -654,22 +654,22 @@ This manifest file contains key = value pares declaring info such as the add-on'
 +++ Available Fields +++
 Although it is highly suggested that manifests contain all fields, the fields marked as mandatory must be included.
 Otherwise, the add-on will not install.  
-- name: A short unique name for the add-on. This is used to differentiate add-ons internally and is not shown to the user. (Mandatory)
-- summary: The name of the add-on as shown to the user. (Mandatory)
-- version: The version of this add-on; e.g. 2.0. (Mandatory)
-- author: The author of this add-on, preferably in the form Full Name <email address>; e.g. Michael Curran <mick@kulgan.net>. (Mandatory)
-- description: A sentence or two describing what the add-on does.
-- url: A URL where this add-on, further info and upgrades can be found.
-- docFileName: The name of the main documentation file for this add-on; e.g. readme.html. See the [Add-on Documentation #AddonDoc] section for more details.
+- name (string): A short unique name for the add-on. This is used to differentiate add-ons internally and is not shown to the user. (Mandatory)
+- summary (string enclosed in quotes): The name of the add-on as shown to the user. (Mandatory)
+- description (string enclosed in quotes): A sentence or two describing what the add-on does. If this spans multiple lines, you need to enclose this information in triple quotes (""").
+- version (string): The version of this add-on; e.g. 2.0. (Mandatory)
+- author (string enclosed in quotes): The author of this add-on, preferably in the form Full Name <email address>; e.g. Michael Curran <mick@kulgan.net>. (Mandatory)
+- url (string): A URL where this add-on, further info and upgrades can be found.
+- docFileName (string): The name of the main documentation file for this add-on; e.g. readme.html. See the [Add-on Documentation #AddonDoc] section for more details.
 -
 
 +++ An Example Manifest File +++
 ```
 --- start ---
 name = MyTestAddon
-summary = Cool Test Add-on
+summary = "Cool Test Add-on"
 version = 1.0
-description = An example add-on showing how to create add-ons!
+description = "An example add-on showing how to create add-ons!"
 author = Michael Curran <mick@kulgan.net>
 url = http://www.nvda-project.org/wiki/Development
 --- end ---