Add attribution to Tabler.io icons used in the new mailer designs (#29470)

app/javascript/images/mailer-new/heading/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2020-2024 Paweł Kuna
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

app/javascript/images/mailer-new/heading/README.md

@@ -0,0 +1 @@
+Images in this folder are based on [Tabler.io icons](https://tabler.io/icons).

app/javascript/images/mailer-new/welcome-icons/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2020-2024 Paweł Kuna
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

app/javascript/images/mailer-new/welcome-icons/README.md

@@ -0,0 +1 @@
+Images in this folder are based on [Tabler.io icons](https://tabler.io/icons).

app/views/application/mailer/_checklist.html.haml

@@ -16,7 +16,7 @@
                           = image_tag frontend_asset_url('images/mailer-new/welcome/checkbox-off.png'), alt: '', width: 20, height: 20
                       %td.email-checklist-icons-step-td
                         - if defined?(key)
-                          = image_tag frontend_asset_url("images/mailer-new/welcome/#{key}-#{checked ? 'on' : 'off'}.png"), alt: '', width: 40, height: 40
+                          = image_tag frontend_asset_url("images/mailer-new/welcome-icons/#{key}-#{checked ? 'on' : 'off'}.png"), alt: '', width: 40, height: 40
                 %td.email-checklist-text-td
                   .email-desktop-flex
                     /[if mso]
@@ -31,8 +31,8 @@
                     %div
                       - if defined?(show_apps_buttons) && show_apps_buttons
                         .email-welcome-apps-btns
-                          = link_to image_tag(frontend_asset_url('images/mailer-new/welcome/btn-app-store.png'), alt: t('user_mailer.welcome.apps_ios_action'), width: 120, height: 40), 'https://apps.apple.com/app/mastodon-for-iphone-and-ipad/id1571998974'
-                          = link_to image_tag(frontend_asset_url('images/mailer-new/welcome/btn-google-play.png'), alt: t('user_mailer.welcome.apps_android_action'), width: 120, height: 40), 'https://play.google.com/store/apps/details?id=org.joinmastodon.android'
+                          = link_to image_tag(frontend_asset_url('images/mailer-new/store-icons/btn-app-store.png'), alt: t('user_mailer.welcome.apps_ios_action'), width: 120, height: 40), 'https://apps.apple.com/app/mastodon-for-iphone-and-ipad/id1571998974'
+                          = link_to image_tag(frontend_asset_url('images/mailer-new/store-icons/btn-google-play.png'), alt: t('user_mailer.welcome.apps_android_action'), width: 120, height: 40), 'https://play.google.com/store/apps/details?id=org.joinmastodon.android'
                       - elsif defined?(button_text) && defined?(button_url) && defined?(checked) && !checked
                         = render 'application/mailer/button', text: button_text, url: button_url, has_arrow: false
                     /[if mso]