Update tests/README

- Use atx headers

- Break on period and comma

- Improve markup of fields

tests/README.md

@@ -1,37 +1,35 @@
-Test suite
-==========
+# Test suite
 
 The test suite consists of a shell script `pick-test.sh` responsible for running
 tests written in the file format described below and `pick-test.c` which will
-invoke pick with a pseudo-terminal. This allows sending keyboard input sequences
-and reading the output on exit.
+invoke pick with a pseudo-terminal.
+This allows sending keyboard input sequences and reading the output on exit.
 
 The recommended way to run the test suite is using `make(1)`:
 
 ```sh
-make check || cat test-suite.log
+$ make check || cat test-suite.log
 ```
 
 Use the `-j` option with a value matching the number of cores on your machine to
 speed-up the process:
 
 ```sh
-make -jN check || cat test-suite.log
+$ make -jN check || cat test-suite.log
 ```
 
 To run one or more specific tests:
 
 ```sh
-env TESTS=tests/01.t make -e check || cat test-suite.log
+$ env TESTS=tests/01.t make -e check || cat test-suite.log
 ```
 
-Format of test files
---------------------
+## Format of test files
 
 A test file consist of fields where field names are terminated with `:` and the
-rest of line is recognized as the corresponding field value. Some fields allow
-multi-line values. Everything after `#` and up to the next newline is treated as
-a comment.
+rest of line is recognized as the corresponding field value.
+Some fields allow multi-line values.
+Everything after `#` and up to the next newline is treated as a comment.
 
 A trivial example:
 
@@ -47,30 +45,35 @@ stdout:
 
 The following fields are recognized:
 
-- args
+- `args`
 
-Arguments passed to the pick process as is.
+  Arguments passed to the pick process as is.
 
-- description
+- `description`
 
-Purpose of the test.
+  Purpose of the test.
 
-- exit
+- `exit`
 
-Exit code of the pick process, defaults to `0` if omitted.
+  Exit code of the pick process,
+  defaults to `0` if omitted.
 
-- keys
+- `keys`
 
-Sequence of characters sent as keyboard input to the pick process. The value
-will be sent through `printf(1)` prior sending it to the pick process. Spaces
-will be stripped, if not escaped. A backslash character is expressed as `\\`,
-thus newline equals `\\n` and space `\\ `.
+  Sequence of characters sent as keyboard input to the pick process.
+  The value will be sent through `printf(1)` prior sending it to the pick
+  process.
+  Spaces will be stripped,
+  if not escaped.
+  A backslash character is expressed as `\\`,
+  thus newline equals `\\n` and space `\\ `.
 
-- stdin
+- `stdin`
 
-Multi-line input to the pick process.
+  Multi-line input to the pick process.
 
-- stdout
+- `stdout`
 
-Expected multi-line output from the pick process. If omitted, output assertion
-is not performed.
+  Expected multi-line output from the pick process.
+  If omitted,
+  output assertion is not performed.