Change 'To run' to 'To use' in all README.md files

As in:

    sgit -e 's/# To run/# To use/g' '*README.md'

This makes consistent the message for how to use the program. 'How to
use' was chosen because one can run a program just by doing './foo' but
that doesn't imply that's how to use it but the purpose of the section
is how to use it.

2019/adamovsky/README.md

@@ -8,7 +8,7 @@ Ondřej Adamovský <oa@cmail.cz>
 make
 ```
 
-## To run:
+## To use:
 
 ```sh
 ./prog file.unl

2019/burton/README.md

@@ -8,7 +8,7 @@ Dave Burton
 make
 ```
 
-## To run:
+## To use:
 
 ```sh
 ./prog < prog.c

2019/ciura/README.md

@@ -10,7 +10,7 @@ make
 ```
 
 
-## To run:
+## To use:
 
 ```sh
 ./getwords.sh en | grep .. | ./prog string

2019/diels-grabsch1/README.md

@@ -11,7 +11,7 @@ make
 ```
 
 
-## To run:
+## To use:
 
 ```sh
 ./prog < file > file.Z

2019/diels-grabsch2/README.md

@@ -11,7 +11,7 @@ make
 ```
 
 
-## To run:
+## To use:
 
 ```sh
 ./prog

2019/dogon/README.md

@@ -8,7 +8,7 @@ Gil Dogon
 make
 ```
 
-## To run:
+## To use:
 
 ```sh
 ./prog < pattern.mc

2019/duble/README.md

@@ -9,7 +9,7 @@ Etienne Duble\
 make
 ```
 
-## To run:
+## To use:
 
 ```sh
 ./prog file

2019/endoh/README.md

@@ -10,7 +10,7 @@ Mastodon: [@mame@ruby.social](https://ruby.social/@mame)
 make
 ```
 
-## To run:
+## To use:
 
 ```sh
 ./prog

2019/giles/README.md

@@ -8,7 +8,7 @@ Edward Giles
 make
 ```
 
-## To run:
+## To use:
 
 ```sh
 ./prog infile.wav outfile.wav

2019/karns/README.md

@@ -10,7 +10,7 @@ make
 ```
 
 
-## To run:
+## To use:
 
 ```sh
 ./prog < textfile_that_fits_on_the_screen

2019/lynn/README.md

@@ -9,7 +9,7 @@ Ben Lynn
 make
 ```
 
-## To run:
+## To use:
 
 ```sh
 ./prog

2019/mills/README.md

@@ -8,7 +8,7 @@ Christopher Mills
 make
 ```
 
-## To run:
+## To use:
 
 ```sh
 make cpclean

2019/poikola/README.md

@@ -9,7 +9,7 @@ Timo Poikola\
 make
 ```
 
-## To run:
+## To use:
 
 ```sh
 ./prog 512 ./prog

2019/yang/README.md

@@ -9,7 +9,7 @@ Don Yang\
 make
 ```
 
-## To run:
+## To use:
 
 ```sh
 ./prog sample_input.txt a b c d