Updated README with basic instructions

Author: eduardotogpi

README.md

@@ -6,9 +6,58 @@ User-friendly scripts designed to make pyCRT accessible to non-programmers.
 
 ## Through the EXE file (Windows only)
 
+Assuming the settings in the configuration file haven't been altered, the
+following steps describe the entire usage of the program:
+
+1. Navigate to the directory `dist/measure_crt/`
+2. Execute the file `measure_crt.exe`
+
+Windows may block the execution of the program due to "unknown source". This
+is expected. Simply click "More info" -> "Run anyway".
+
+3. Select whether you would like to measure CRT in a single video or in all
+   the videos inside a directory.
+4. If a Region of Interest (ROI) was not specified in the configuration file
+   (see below), press the spacebar key when pressure is being applied, click
+   and drag the mouse to draw a square around the desired ROI.
+5. Check the terminal. If a ROI was selected manually, it should appear there
+   as a tuple of 4 numbers.
+6. Wait for video playback to finish.
+7. If CRT measurement was successful, you should see plots of the average
+   intensities in each channel and the CRT fit result.
+8. The aforementioned graphs are saved in the `dists/measure_crt/Plots`
+   directory.
+9. The file `results_sheet.csv` is created automatically. It contains a
+   spreadsheet of the parameters and results of every CRT measurement
+   performed using the program. The file `results_sheet.xlsx` is the same
+   spreadsheet, but in a format more suitable for spreadsheet software such as
+   MS Excel.
+10. A log of all the messages printed on the terminal is kept in the file
+    log.txt, organized by the date and time of execution of this program.
 
 ## Through the command line
 
+The script can also be executed in your Python environment. Simply run either
+`measure_crt.py` in the command line:
+
+```
+python measure_crt.py
+```
+
+Upon running the script, you may proceed according to the instructions for the
+EXE file.
+
+In case you specifically want to measure CRT from a single video file or from
+an entire directory of videos, you may run the scripts `measure_crt_video.py`
+and `measure_crt_dir.py` respectively.
+
+
+## Configuration file
+
+The CRT measurement parameters, as well as the program's settings can be
+configured with the `configuration.toml`, which is read at the start of each
+execution. More details to be added later...
+
 # To-do
 
 This is a list of features I would like to implement (I don't promise I will