replace covalent with prefect and add ref to awesome list

Had trouble even getting Covalent to run, and still waiting on cloud access. Andrew Rosen recommended prefect, and I like it already.

readme.md

@@ -178,7 +178,7 @@ Examples of [experimental orchestration](#experimental-orchestration-software),
 
 ### Workflow Orchestration
 
-Experimental orchestration software for autonomously controlling software-hardware communication. See also [@sgbaird's lab-automation list](https://github.com/stars/sgbaird/lists/lab-automation).
+Experimental orchestration software for autonomously controlling software-hardware communication.
 
 - Alab Management [[code](https://github.com/CederGroupHub/alab_management)] [[docs](https://alab-management.readthedocs.io/en/latest/)]
 - Bluesky [[code](https://github.com/bluesky/bluesky)] [[docs](https://blueskyproject.io/bluesky/)]
@@ -189,7 +189,11 @@ Experimental orchestration software for autonomously controlling software-hardwa
 - XDL [[code](https://gitlab.com/croningroup/chemputer/xdl)] [[docs](https://croningroup.gitlab.io/chemputer/xdl/)] [[paper](https://dx.doi.org/10.1126/science.aav2211)]
 - self-driving-lab-demo [[code](https://github.com/sparks-baird/self-driving-lab-demo)] [[docs](https://self-driving-lab-demo.readthedocs.io/)]
 - NIMS-OS [[code](https://github.com/nimsos-dev/nimsos)] [[docs](https://nimsos-dev.github.io/nimsos/docs/en/index.html)] [[paper](https://doi.org/10.48550/arXiv.2304.13927)]
-- Covalent [[code](https://github.com/AgnostiqHQ/covalent)] [[docs](https://www.covalent.xyz/)] [[doi](https://doi.org/10.5281/zenodo.5903364)]
+- Prefect [[code](https://github.com/PrefectHQ/prefect) [[docs](https://www.prefect.io/)]
+
+<!--- Covalent [[code](https://github.com/AgnostiqHQ/covalent)] [[docs](https://www.covalent.xyz/)] [[doi](https://doi.org/10.5281/zenodo.5903364)] --->
+
+See also [@sgbaird's lab-automation list](https://github.com/stars/sgbaird/lists/lab-automation) and [Awesome Workflow Repositories](https://meirwah.github.io/awesome-workflow-engines/).
 
 ### Optimization
 [Open-source](#open-source) and [proprietary](#proprietary) optimization software for iteratively suggesting next experiments (i.e., adaptive experimentation).