[IMP] sms_marketing: add Twilio documentation

content/applications/marketing/sms_marketing.rst

@@ -45,6 +45,12 @@ rate)` outcomes.
       Find out more about Odoo's SMS pricing, and check out some of the most frequently asked
       questions.
 
+   .. card:: Twilio
+      :target: sms_marketing/twilio
+
+      In some countries with stricter regulations, the out-of-the-box solution proposed by Odoo
+      may not work. In this case, you can use our Twilio integration to send SMS worldwide.
+
 SMS marketing dashboard
 =======================
 
@@ -81,3 +87,4 @@ detailed analysis.
    sms_marketing/marketing_campaigns
    sms_marketing/mailing_lists_blacklists
    sms_marketing/pricing_and_faq
+   sms_marketing/twilio

content/applications/marketing/sms_marketing/twilio.rst

@@ -0,0 +1,65 @@
+==============
+SMS via Twilio
+==============
+
+What is Twilio
+==============
+
+Twilio is a third-party provider that enables you to send SMS messages to your clients.
+Odoo provides an easy way to use this service within your Odoo apps.
+
+Why would I need it?
+--------------------
+
+Altough Odoo already comes with an out-of-the-box (IAP) solution for SMS messages, it might
+not work in some countries with stricter legal requirements. Currently, Odoo registers
+itself when possible to avoid extra setup for its customers, however in some countries
+that is not enough and the client itself must do it. This can be done through Twilio.
+
+Setup your Twilio account
+=========================
+
+By creating a Twilio account, you will be able to create a virtual phone number from
+which you will be able to send SMS messages. These cost credits that are to be bought
+on Twilio, not Odoo.
+
+#. Go to `Twilio <https://www.twilio.com>`_
+#. Sign up and create a Twilio account
+#. Within your Twilio account, you can create multiple accounts (e.g. one for testing, one for each sub-company, etc.)
+#. Create a new account
+
+   #. Enter the name, and select :guilabel:`Twilio` for the type
+   #. Select your :guilabel:`Billing Country` and click :guilabel:`Create new account`
+   #. Select the different options that match your needs
+
+      - For the :guilabel:`Twilio product`, select :guilabel:`SMS`
+      - For :guilabel:`How to build with Twilio`, select :guilabel:`With no code at all`
+      - For your :guilabel:`goal`, select :guilabel:`3rd party integrations`
+   #. Click on :guilabel:`Get Started with Twilio`
+#. You account is now created, and you should arrive on your :guilabel:`Dashboard`
+#. Go to :menuselection:`Phone Numbers --> Manage --> Buy a number`
+#. Buy a number (it is a paying service, but you should have received some credits to start with)
+#. Go back to bottom of the :guilabel:`Dashboard` page
+#. Copy the :guilabel:`Account SID` and :guilabel:`Auth Token`
+
+Beware that sending SMS to some countries (such as the US or Canada) might require a registration.
+This can only be done by you, and not by Odoo. Please check out
+`Twilio's Help Center <https://help.twilio.com>`_
+
+
+Setup Odoo to use Twilio
+========================
+
+#. :ref:`Install <general/install>` the :guilabel:`Twilio SMS` module (`sms_twilio`)
+#. In Odoo, go to :menuselection:`Settings --> General Settings --> Contacts --> Send SMS`,
+   select :guilabel:`Twilio` in the list of options, and save your change.
+#. Go back to that option, and click :guilabel:`Manage Twilio Connection`
+#. Paste the copied credentials accordingly
+#. Click on :guilabel:`Reload numbers`
+#. Your newly bought phone number should appear in the list
+#. You can use the testing section to send an SMS
+
+You can have multiple numbers (for instance once per country, or one per campaign), in that case,
+you can reorder the numbers. By default, when sending an SMS to a client, Odoo will select the
+number whose country is the same as the client. If none matches, Odoo will use the first number
+available from the list respecting the order you have chosen.