Fix eWay documentation

See merge request documentation/docs/sysadmin!299

Minor typo: somtimes => sometimes

See merge request documentation/docs/sysadmin!298

Update jobs.md

See merge request documentation/docs/sysadmin!296

Removed very dated references

See merge request documentation/docs/sysadmin!295

Combine "SITE" and "CRED" key discussions. Add "SIGN" key

See merge request documentation/docs/sysadmin!297

Update paypal-pro.md to reflect current PHP requirements

See merge request documentation/docs/sysadmin!294

Expand the scope of this section to include both WordPress specific Extensions...

See merge request documentation/docs/sysadmin!293

Expand the scope of this section to include both WordPress specific Extensions and well as Plugins for CiviCRM.

Fix typo

See merge request documentation/docs/sysadmin!292

Migrate multisite installation guide to Installation Guide

Closes #276

See merge request documentation/docs/sysadmin!288

Create new page for the WordPress base page.

See merge request documentation/docs/sysadmin!289

Fix typos in WordPress section and navigation

See merge request documentation/docs/sysadmin!290

Add information on the new `CRED_KEYS` setting for 5.34+

See merge request documentation/docs/sysadmin!291

As per https://docs.civicrm.org/dev/en/latest/documentation/style-guide/#title-capitalization

Redirect to Installation Guide

Add section on CiviCRM 5.26 and WordPress 5.5

See merge request documentation/docs/sysadmin!284