Update README.md

Minor cleanup. Thanks grammarly.

README.md

@@ -16,11 +16,12 @@ $ plotdigitizer --help
 
 ## Preparing image
 
-Crop the image and leave only axis and trajectories. I use
-`gthumb` utility on Linux. You can also use imagemagick or gimp.
+Crop the image and leave only axis and trajectories. I used the `gthumb` utility on Linux. 
+You can also use `imagemagick` or `gimp`.
 
-Following image is from MacFadden and Koshland, PNAS 1990 after trimming. One
-can also remove top and right axis.
+The following image is from MacFadden and Koshland, PNAS 1990 after trimming. One
+should also remove top and right axes. I didn't because I want to highlight the 
+limitation of this tool!
 
 ![Trimmed image](./figures/trimmed.png)
 
@@ -30,19 +31,20 @@ __Run__
 plotdigitizer ./figures/trimmed.png -p 0,0 -p 10,0 -p 0,1
 ```
 
-We need at least three points (`-p` option) to map axes onto the image.  In the example
-above, these are `0,0` (where x-axis and y-axis intesect) , `10,0` (a point on
-x-axis) and `0,1` (a point on y-axis). To map these points on the image, you
-will be asked to click on these points on the image. _Make sure to click in
-the same order and click on the points as precisely as you could. Any error in
-this step will propagate._ If you don't have `0,0` in your image, you have to provide
-4 points: 2 on x-axis and 2 on y-axis.
+We need at least three points (`-p` option) to map x- and y-axis onto the image.  
 
-The data-points will be dumped to a csv file specified by __`--output
+In the example above, these are `0,0` (where x-axis and y-axis intersect) , `10,0` (a point on
+the x-axis), and `0,1` (a point on the y-axis). To map these points on the image, you
+will be asked to click on these points. _Make sure to click in the same order and click on
+the points as precisely as you could. Any error in this step will propagate._ 
+
+If you don't have `0,0` in your image, you must provide 4 points: 2 on the x-axis and 2 on the y-axis.
+
+The data points will be dumped to a CSV file specified by __`--output
 /path/to/file.csv`__.
 
-If `--plot output.png` is passed, a plot of the extracted data-points will be
-saved to `output.png`. This requires `matplotlib`. Very useful when debugging/testing.
+If `--plot output.png` is passed, a plot of the extracted data points will be
+saved to `output.png`. This requires matplotlib. Very useful when debugging/testing.
 
 ![](./figures/traj.png)
 
@@ -51,7 +53,7 @@ Notice the error near the right y-axis.
 ## Using in batch mode
 
 You can pass the coordinates of points in the image at the command prompt.
-This allows to run in the batch mode without any need for the user to click on
+This allows it to run in batch mode without any need for the user to click on
 the image.
 
 ```bash
@@ -61,9 +63,9 @@ plotdigitizer ./figures/trimmed.png -p 0,0 -p 20,0 -p 0,1 -l 22,295 -l 142,295 -
 ### How to find coordinates of axes points
 
 In the example above, point `0,0` is mapped to coordinate `22,295` i.e., the
-data point `0,0` is on the 22nd row and 295th column of the image (_assuming that bottom left
-of the image is first row, first column `(0,0)`_). I have included an utility
-`plotdigitizer-locate` (script `plotdigitizer/locate.py`) which you can use to
+data point `0,0` is on the 22nd row and 295th column of the image (_assuming that the bottom left
+of the image is the first row, first column `(0,0)`_). I have included a utility
+`plotdigitizer-locate` (script `plotdigitizer/locate.py`), which you can use to
 find the coordinates of points.
 
 
@@ -77,15 +79,14 @@ or, by directly using the script:
 $ python3 plotdigitizer/locate.py figures/trimmed.png
 ```
 
-This command opens the image in a simple window. You can click on a point and
-its coordinate will be written on the image itself. Note them down.
+This command opens the image in a simple window. You can click on a point, and
+its coordinates will be written on the image. Note them down.
 
 ![](./figures/trimmed_locate.png)
 
 
 # Examples
 
-
 ### Base examples
 
 ```bash
@@ -130,7 +131,7 @@ the detection below it.__
 
 # Limitations
 
-This application has following limitations:
+This application has the following limitations:
 
 - Only b/w images are supported for now. Color images will be converted to grayscale upon reading.
 - Each plot should have only one trajectory.
@@ -143,10 +144,3 @@ Open an issue and please attach the sample plot.
 
 1.  [WebPlotDigitizer](https://automeris.io/WebPlotDigitizer/) by Ankit
 Rohatagi is very versatile.
-
-
-## Notes
-
-- grapvhiz version 2.47.2 is broken for some xml files. See
-<https://forum.graphviz.org/t/assert-sz-2-in-convertsptoroute/689>. Please use a
-different version.