Add logo to our repos for social media previews

### Overview
By adding the project's logo/image to your project's primary repository, we will be able to dynamically deliver up to date information about your project to the hackforla.org website. Also when people add the link to the repository in LinkedIn or Slack, or other social media it will automatically use the image as well as the description, improving the link's chances of getting clicked on.

### Action Items
- [ ] Add project's logo/image to knowledgebase GitHub repository (this repo)
- [ ] Add project's logo/image +the word content to the https://github.com/hackforla/knowledgebase-content repo

### Resources/Instructions
Use the same image as is on the hackforla.org website, or if another image is desired, please replace both with the same image.
Tip: Your image should be a PNG, JPG, or GIF file under 1 MB in size. For the best quality rendering, we recommend keeping the image at 640 by 320 pixels.
Read Github's [Customizing your repository's social media preview](https://help.github.com/en/articles/customizing-your-repositorys-social-media-preview)