Add templates, i.e. for unit fixed effects models

[flxflks]

I would like to create a DAG for a unit fixed effect model for panel data in dagitty. I clicked through the examples but did not see any models that would fit my description. Basically, I want to recreate the graphs from Imai and Kim (2019). Since, panel data and unit fixed effect are common in economics. I will recreate the graph for myself now but I was thinking that it would make sense to save this graph as template for future researchers.

Reference:
Imai, K., & Kim, I. S. (2019). When Should We Use Unit Fixed Effects Regression Models for Causal Inference with Longitudinal Data? American Journal of Political Science, 63(2), 467–490. https://doi.org/10.1111/ajps.12417