Add description for new ovmf_prebuilt repo

Author: phil-opp

content/this-month/2021-04/index.md

@@ -86,6 +86,10 @@ to a data type that it can't be interpreted as - AML's rules on possible type co
 
 Thanks to [@Knapsac](https://github.com/KnapSac) and [@toothbrush7777777](https://github.com/toothbrush7777777) for their contributions!
 
+### [`ovmf-prebuilt`](https://github.com/rust-osdev/ovmf-prebuilt)
+
+In order to make it easier to run UEFI disk images in [QEMU](https://www.qemu.org/) using [OVMF](https://github.com/tianocore/tianocore.github.io/wiki/OVMF), we created a new `ovmf-prebuilt` project this month. The projects automatically downloads the latest prebuilt OVMF RPM images from [Gerd Hoffman's firmware repository](https://www.kraxel.org/repos/) and publishes the extracted `OVMF_*.fd` files as [GitHub releases](https://github.com/rust-osdev/ovmf-prebuilt/releases). A new release is created daily through a CI script. Note that the licensing terms of the [`tianocore/edk2`](https://github.com/tianocore/edk2) repository apply to the released files.
+
 ### [`uart_16550`](https://github.com/rust-osdev/uart_16550)
 
 The `uart_16550` crate provides basic support for serial port I/O for 16550-compatible UARTs. In April, we updated the `x86_64` dependency to fix the build on the latest nightlies: