Revise and improve branding, readability and SEO for integration pages.

[pavlenex]

Context:
Often, new users discover BTCPay Server by finding a way to accept bitcoin in their e-commerce software (CMS). This is usually done by Googling "Accept bitcoin/crypto in XYZ".

It seems with a bit of cleanups and improvements, that allows for better experience overal, we can boost discoverability of those pages.

When a user lands on a page Shopify, by googling How to accept Bitcoin in Shopify for example ,they're expecting to get context, understand the features/advantages and how to get started as quickly as possible.

This issue is a tracker for multiple smaller issues that we can tackle, by striving to improve our integrations landing pages. In most cases the readme of the integration repo has to be addressed since we pull docs from them. Please reach out before tackling any of this issues for consensus and approach alignment.

Good example on how a page should look is our newly updated WooCommerce plugin.

Ideal description of an integration should have:

1. How to accept Bitcoin in [Integration name]
2. Quick introduction on [Integration name] + BTCPay Server
3. Short description of how BTCPay works linking to relevant document
4. Highlight features concisely and relevant for specific target group - online merchants
5. Have visually pleasing graphics that outline purpose of the integration and showcase important features merchants want
   6.Have clear instructions on how to connect integration to BTCPay Server
6. Have a video tutorial on how to do integration
7. Provide links on how to get more information and support
8. [Optional]Explaining advantages/disadvantages or competitor analysis graph

Sorted in order of priority, each of these should be tackled:

Tasks

Beta Give feedback

1. WooCommerce add graphics + screenshots
2. Shopify revise
3. Magento 2
4. PrestaShop
5. Joomla/Virtumart
6. OpenCart
7. Drupal
8. Zapier
9. Odoo
10. Shopaware
11. SmartStore
12. NopCommerce [TBD]
13. BigCommerce [TBD]