update README to add windows instructions

README.md

@@ -11,15 +11,29 @@ This program serves to take a list of boardgames as a csv and return a csv with
 
 ### Run the sample
 
-`cat sample_in.csv | nix run`
+`cp sample_in.csv in.csv`
+`nix run`
 
 the output `out.csv` should match the provided `sample_out.csv`
 
+## Quick Windows user guide
+
+- Make a new folder
+- Put `rust_elaborator.exe` into that folder
+- Copy your `in.csv`, a list of game names as specified in `Usage`, or `out.csv`, an output from when this program ran previously, into the new folder
+- Double-click `rust_elaborator.exe` to run it
+- Check that `out.csv` is satisfactory
+
 ## Usage
 
-The program reads a csv from stdin and outputs it to `out.csv`. The following command reads the contents of `in.csv` into the program and runs it.
+# WARNING: files may be overwritten
 
-`cat in.csv | rust_elaborator`
+The files `in.csv`, `out.csv`, `test.csv`, `copy.csv`, and possibly others may be overwritten and data loss may occur. Run this program in an empty directory with a copy of `in.csv` or `out.csv` and nothing else present for safety.
+
+The program reads a file `in.csv` or `out.csv` and outpus it to `out.csv`. The following command reads the contents of `in.csv` into the program and runs it.
+note that on windows, `rust_elaborator` instead looks like `rust_elaborator.exe`
+
+`rust_elaborator`
 
 `in.csv` must be formatted as follows...
 
@@ -46,8 +60,4 @@ where `title` can be anything.
 Capitalization does not matter.
 Additional columns will not be present in `out.csv`.
 
-If you have an existing `out.csv`, you can add new rows and avoid recalling the rows that are already filled in with the flag `--mode expand`.
-
-`cat out.csv | nix run . -- --mode expand`
-
-This will only check rows that have a) a blank second column or b) NOT_FOUND in the second column.
+If `out.csv` is present, the program will take it as input and elaborate on it. This will fill in rows that have a) a blank second column or b) NOT_FOUND in the second column, if possible.