Update Docs based on new LDU usage recommendations

[eastandwestwind]

Docs Update Description

Our docs leave out some detail where there could be a risk with LDU usage:

1. If customers initialize the Meta pixel in multiple locations, they need to include our code in all of those. For example:

{{Fides.DataSalesAndSharing}} ? fbq('dataProcessingOptions', []) : fbq('dataProcessingOptions', ['LDU'], 0, 0);
fbq('init', '{pixel_id}');

2. Customers have 2 options:

Option 1: Set the location to California to “force” LDU to be enabled, e.g. fbq('dataProcessingOptions', ['LDU'], 1, 1000);. This works well for our current customers, as it's configured to be set only if the associated ethyca/fides data use is false.

Option 2: Set the location to 0 to allow Meta to decide the LDU, e.g. fbq('dataProcessingOptions', ['LDU'], 0, 0);. In this case, Meta will use it's own geolocation. But keep in mind it only applies to 3 states, so if the customer wishes to use other states for the LDU flag, then they’ll need to force LDU with option 1.

We should update the following docs pages according to the above recommendation, in addition to linking to Meta's docs- https://developers.facebook.com/docs/marketing-apis/data-processing-options:

• https://support.ethyca.com/docs/how-to-configure-consent-in-google-tag-manager-gtm#step-3-configuring-limited-data-use-for-facebook
• https://docs.ethyca.com/tutorials/consent-management-configuration/google-tag-manager#configure-limited-data-use-for-meta-facebook

Additional context

Add any other context about the problem here.