Update the main page openela.org

[aclark801]

I would like to propose updates to the main page.

1. Where the ELA logo is, replace with "Open EL Association"
2. Replace hydrangia.jpg with the OpenELA logo
3. change the "Open Enterprise.... Read the Announcement" with Our mission is to provide a secure, transparent, and reliable Enterprise Linux source."
4. Keep the logos as is
5. replace the OpenELA Imports table with 'badges'(or boxes...) where each one represents each of the projects. Each box acts as a link to the appropriate github page.

Box 1 Enterprise Linux

• Sources necessary for downstreams compatible with RHEL to exist -- Focus on versions EL8, EL9 -- Ensuring the continued availability of OpenELA sources to the community indefinitely.

Box 2 User Manuals

• Content for each Enterprise Linux release -- Contributions are very welcome -- Stored in Markdown format -- Release based content

Box 3 Linux LTS

• Developer kernel maintenance beyond the commitment of upstream maintainers -- 4.14 Kernel Security Maintenance -- A continuation of stable kernel releases from upstream stable.

Box 4 Mothership

• Automation and attestation -- Tools to archive RPM packages and attest to their authenticity -- Automation for Enterprise Linux sources

Keep the remaining portion of the page the same.

[aclark801]

#4 keep the company logos as they are currently

[dirkmueller]

thanks Alan for the input, I've made https://github.com/openela/openela.org/pull/49 for this. unfortunately the site layout template is very rigid, it doesn't provide a lot of flexibility. we can only have 3 highlight boxes.

I picked EL, User Manuals and Linux LTS.