Make clear the target audience of this package

[n8thangreen]

There are already a few widely-used R packages in CRAN to perform model-based standardization, such as “marginaleffects” and “stdReg”. I presume that the target audience of outstandR is those who want to perform model-based standardization in the specific context of two-study indirect treatment comparisons with limited subject-level data and binary outcomes. This is model-based standardization with two additional steps: (1) covariate simulation (to overcome limited subject-level data for one of the studies) and (2) the indirect comparison across studies.