doc(cucumber) timeout and caps

end2end-tests/README.md

 # Duniter-v2s end2end tests
 
-## cucumber functionnal tests
+## Cucumber functionnal tests
 
 We use [cucumber] to be able to describe test scenarios in human language.
 
@@ -20,7 +20,7 @@ Feature: Balance transfer
     Then dave should have 5 ĞD
 ```
 
-### create a new functional test
+### Create a new functional test
 
 To create a new test scenario, simply create a new file with a name of your choice in the
 `/cucumber-features` folder and give it the extension `.feature`.
@@ -96,7 +96,7 @@ Amounts must be expressed as an integer of `ĞD` or `UD`, decimal numbers are no
 If you need more precision, you can express amounts in cents of ĞD (write `cĞD`), or in thousandths
 of UD (write `mUD`).
 
-### genesis state
+### Genesis state
 
 Each scenario bootstraps its own blockchain with its own genesis state.
 
@@ -132,7 +132,7 @@ cargo cucumber -i monetary*
 will only run `.feature` files that start with `"monetary"`.
 
 The features will be tested in parallel and logs files will be written in the `end2end-tests` folder.
-If you get an `Error: Timeout`, look at the logs to understand why Duniter did not launch successfully.
+If you get an `Error: Timeout`, look at the logs to understand why Duniter did not launch successfully. You can also set the environment variable `DUNITER_END2END_TESTS_SPAWN_NODE_TIMEOUT` to increase the timeout for node spawn.
 
 ### Contribute to the code that runs the tests