DOCS: Changes to How-to Guides Section + New Articles

[ShilpaVernekar]

Describe your changes:

- Glossary and Classification Section
Separated the sections
Updated overviews for Glossary, Classification
Separated out some sections as New Articles
How to Request for Classification Tags
Auto-Classification in OpenMetadata
Best Practices for Classification

• All Articles
  Added link to the Next Article at the end of each article
  Changed link to images from v1.1 to v1.2

- Connectors Section
Corrected links and text
Updated the Connector list
Arranged it alphabetically
Custom Connector doc - Webinar link added

- Developers Section
Language Support article moved here from How-to guides
Feature Configurations > Bots article moved here from How-to guides
CLI Ingestion with Basic Auth article moved here
How to add a custom property to an entity with API moved here

- 6 Pillars of OpenMetadata
Moved all the sections out of this folder
How to Guides
Updated content for the main page.
cc @aniketkatkar97

- Data Insights
Edited steps and screenshots for the docs
New Articles
Configure the Data Insights Report
Moved Cost Analysis article here

• Admin Guide
  Renamed to ‘Admin Guide’, in place of ‘Quick Start Guide for Admins’
  Add Custom Logo article moved here
  Moved Roles & Policies guide under this
  Rearranged articles

I worked on ... because ...

Type of change:

• Bug fix
• Improvement
• New feature
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation

Checklist:

• I have read the CONTRIBUTING document.
• My PR title is Fixes <issue-number>: <short explanation>
• I have commented on my code, particularly in hard-to-understand areas.
• For JSON Schema changes: I updated the migration scripts or explained why it is not needed.