📚 chore: Update README.md content and pictures

Author: HarshKapadia2

README.md

@@ -8,23 +8,23 @@ Hosted at [HarshKapadia2.github.io/git-graph](https://harshkapadia2.github.io/gi
 >
 > -   [Learn about Git Objects.](https://git.harshkapadia.me/#_git_objects)
 > -   This web app is a part of [my Git Internals talks](https://talks.harshkapadia.me/git_internals).
-> -   Special thanks to [@KartikSoneji](https://github.com/KartikSoneji) for his help with a few critical things.
+> -   Special thanks to [@KartikSoneji](https://github.com/KartikSoneji) for his help with parsing Tree files and [@tusharnankani](https://github.com/tusharnankani) for his UI/UX suggestions.
 > -   Please report errors and bugs by [raising issues](https://github.com/HarshKapadia2/git-graph/issues).
 
 ## Usage
 
--   Select the `.git` directory of a repository for the graph to appear.
+-   Select the `.git` directory of a repository for the graph to render.
     -   If the `.git` directory is not visible in the directory picker, please enable hidden file viewing on the local machine.
     -   Extremely huge repositories might not load due to browser memory constraints.
-    -   Packed repo error: Please unpack all the [packfiles](https://git.harshkapadia.me/#_the_pack_directory) (`.pack` files) in the repository. ([Tutorial](https://www.youtube.com/watch?v=cauIy20JhFs))
+    -   Packed repo error: Please unpack **all** the [packfiles](https://git.harshkapadia.me/#_the_pack_directory) (`.pack` files) in the repository. ([Tutorial](https://www.youtube.com/watch?v=cauIy20JhFs))
 -   Using the Commit Selector, one or more Commits and their corresponding Trees and Blobs can be highlighted.
 -   Hover over objects and click on the 'Raw' button to view the raw contents of that Git Object.
 
 ## Screenshots
 
 ![](repo-img/sample-1.png)
 
-Select one or more commits to highlight 👇
+Select commit(s) to highlight 👇
 
 ![](repo-img/sample-2.png)