Add mUzima for COVID-19 to mUzima.org

mUzima for COVID-19 is a new implementation project. Need the following on mUzima.org

• Add mUzima for COVID-19 graphic to main page slider
• When clicking on the main page slider, it will bring to the new sub-page (https://www.muzima.org/implementations/covid-19)
• On https://www.muzima.org/implementations/covid-19, add graphic and description.
• On https://www.muzima.org/ main page, add mUzima for COVID-19 on the first panel under Implementations section and keep BIGPIC on second panel and Chronic Disease Management on the third panel.