docs: Remove unecessary backticks
Remove backticks from repos that are not the name of files/commands.
Also, mark first instance of "Linux" with asterisk.
@@ -97,16 +97,16 @@ create virtual machines for hosting the containers.
##### Kernel
-The [`linux`](https://github.com/kata-containers/linux) kernel is used by the hypervisor to boot the guest image.
+The [Linux\*](https://github.com/kata-containers/linux) kernel is used by the hypervisor to boot the guest image.
### Documentation
-The [`documentation`](https://github.com/kata-containers/documentation)
+The [documentation](https://github.com/kata-containers/documentation)
repository hosts documentation common to all code components.
### Test code
-The [Tests](https://github.com/kata-containers/tests) repository hosts all
+The [tests](https://github.com/kata-containers/tests) repository hosts all
test code except the unit testing code (which is kept in the same repository
as the component it tests).
