Extend cheat sheet format dscription

README.md

@@ -9,13 +9,30 @@ to one of the upstream repositories).
 When adding a cheat sheet please use the following format:
 
 ```
-# Command1 description 
-# started with some comments
-# and followed with a command example/switches
+# Command name
+# Short command description
+
+# Command usage example1 started with some comments
+# and followed with a command example/switches.
 command1
 
-# Command2 description
-# Each block separated with an empty line
+# Command usage example2.
+# Each block separated with an empty line.
 command2
 ```
 
+For example:
+
+```
+# curl
+# Command-line tool for transferring data with URL syntax
+
+# Process a single GET request, and show its output on stdout.
+curl http://path.to.the/file
+```
+
+Requirements and constraints:
+
+* Maximum length of a comment line (including comment sign) is 80
+
+Other requirements can be proposed and discussed in #101