Docs rework

[asvae]

User story

As a user, vuestic documentation is not great for me:

• examples are too prop specifics and don't look good;
• text is too technical and sometimes states the obvious;
• documentation is failing some accessibility checks.

Solution broad

All of these points we can definitely improve by:

• using more scenic examples that portray real case instead of showing how to use some particular prop;
• imroving text by adding some broader information (again, based off user case instead of component functionality);
• fixing accessibility issues and applying automated checks.

Solution steps

Documentation rework:

• Standard for documentation page #2850
• Documentation pages rework #2851

Accesibility improvements:

• Check lighthouse issues #2852
• Automated lighthouse check #2853

Other

• Move documentation to nuxt when it's ready for vue3 #650
• VaContent should be applied to doc block, not whole page #2260

Timeline

• Plan is to include some changes in 1.6.0 if possible, but this would be ongoing effort through 1.7.0 and probably even further.