Add info about My Domain URLs for Salesforce cxns

URL notes and a link to Salesforce documentation to help with
troubleshooting 'restricted domain' errors when using otherwise
valid usernames and tokens.

Signed-off-by: Bart Maertens <[email protected]>

docs/hop-user-manual/modules/ROOT/pages/pipeline/transforms/salesforce-connection.adoc

@@ -27,7 +27,9 @@ Enter the connection information in the following transform options:
 |Option|Description
 |Salesforce Webservice URL a| Specify the URL to the Salesforce Webservice. +
 
-Default: https://login.salesforce.com/services/Soap/u/50.0
+Default: https://login.salesforce.com/services/Soap/u/50.0 
+
+You may need to update this if your company uses "My Domain" on salesforce.  If so, check with your Salesforce Administrator for the URL.  Generally of the format https://NAME.my.salesforce.com/services/Soap/u/50.0.  You can access a sandbox by using its URL here as well.  It is strongly recommended to utilize xref:pipeline/transforms/setvariable.adoc[variables] to populate these values.
 
 |Username|Specify the username for authenticating to Salesforce
 |Password|Specify the password for authenticating to Salesforce.

docs/hop-user-manual/modules/ROOT/pages/pipeline/transforms/salesforceinput.adoc

@@ -51,6 +51,8 @@ Enter the following information in the transform name field:
 * Transform name: Specifies the unique name of the Salesforce Input transform on the canvas.
 You can customize the name or leave it as the default.
 
+NOTE: If your organization has enabled My Domain, you may see 'Restricted Domain' in your Salesforce login history when attempting to use the default URL, as described https://help.salesforce.com/s/articleView?id=000387792&type=1[here]. See below for options.
+
 == Options
 
 include::salesforce-connection.adoc[]