Homepage content update

Created by: shanda-eclipse

Please update the following content on https://www.osdforum.org/.

In Jumbotron, replace "Save the date September 15th, 2020" with "Virtual event | September 15th, 2020"

Under the about section: Replace "The agenda also includes a hands on bring up session using a RISC-V based development board that attendees can keep." with "The agenda also includes a hands-on session using a CORE-V MCU open-source RISC-V core FPGA development board."

Replace "Made possible by the generous support of our sponsors, the OSDForum is a non-profit event with low attendee fees of $50 for industry attendees and $25 for academic attendees (includes the full day of talks, breaks, lunch and a RISC-V development board)." with "Made possible by the generous support of our sponsors, the OSDForum is a non-profit event with the low fee of $25 USD for industry and academic attendees. If you do not have a CORE-V MCU open-source RISC-V core FPGA development board, you can purchase one during the registration process at a discounted rate."