issue 3208: welcome new user email feature added

[vishalpandeynits]

This PR adds the feature that whenever a user registers and its activation is completed,
a welcome email will be sent to him describing the Kolibri features and it also has different tutorial links
The email template was provided in the issue #3208 .

#Screenshot

[vishalpandeynits]

cc @rtibbles

[lauradanforth]

@vishalpandeyvip Thank you again for your support on this. Could you make a few small tweaks on this for us?:

• Remove the "Hello ," at the beginning
• Change the banner at the top to "Welcome to Kolibri Studio" (remove 'the')
• Put the following items in bold face: "Kolibri Studio User Guide" "Content integration guide" and "Step by step tutorials"
• Capitalize the 'E' in English at the end: "*Resources are presented in English"

Thank you so much! Looking forward to getting this in.

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

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[vishalpandeynits]

Thanks for your review @lauradanforth, I have made the changes requested by you. Here is the new screenshot of the email

.

[lauradanforth]

Looks great @vishalpandeyvip thank you!

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

No Coverage information
No Duplication information

[bjester]

@vishalpandeyvip Thank you for working on this issue! I made a couple updates to it, but I checked with @lauradanforth and we also need to allow this email to be translatable. We're making tweaks to the copy now to resolve some issues in conflict with making it translatable. There are examples of how we set this up in other emails like the activation email referenced in the issue, if you would like to make these further updates?

[lauradanforth]

@bjester I updated the draft here with included links listed out, to support this being translated

[lauradanforth]

Updated again - hopefully correctly this time! Lmk if it's still off.