Improve and update SCA documentation

[jnasselle]

Related issue
wazuh/wazuh#14268

Reference branch : 4.3.6-rc

Description

During Release 4.3.6 - Release Candidate 1 - E2E UX tests - Configuration assessment #14268, the next items should be updated or improved

• The policies used in the examples, their alerts, and images no longer exist.
  
  
• When using an example, add a note clarifying that the example applies to a certain operating system and policy
• Wazuh's policies list is incomplete. The following policies should be appended:
  • cis_amazon_linux_2.yml
  • cis_amazon_linux_1.yml
  • cis_solaris11.4.yml
  • cis_solaris11.yml
• Mention new NIST and TSC in addition to PCI-DSS and CIS
  
• Condition 'non-applicable' do not exist. Actually is 'Not applicable"
• When showing alerts, mention that it is alert.log or changes it to alert.json (is most commonly used)
• The use of [Now in SCA advantages](https://documentation-dev.wazuh.com/4.3.6-rc/user-manual/capabilities/sec-config-assessment/index.html) can be confusing as there is no clear reference to what it is compared to (other modules or older SCA)