contributing: upd section "Using HLS on HLS code"

Author: Anton-Latukha

docs/contributing/contributing.md

@@ -113,22 +113,27 @@ $ cabal run haskell-language-server:func-test -- -p "hlint enables"
 
 ## Using HLS on HLS code
 
-[HLS project configuration guidelines](../configuration.md#configuring-your-project-build) also apply to the HLS project itself.
+Generally, project now should work without any `hie.yaml` configuration placed.
 
-Note: HLS implicitly detects HLS codebase as a Stack project (see [hie-bios implicit configuration documentation](https://github.com/haskell/hie-bios/blob/master/README.md#implicit-configuration)).
-If you want HLS to use Cabal, you need to create an `hie.yaml` file:
+In other cases:
+1. If there are `hie.yaml` (& `hie.yml`) files - try to backup them, remove & load project without them.
+2. Note that many subdirectories of a project are in itself are subprojects, & if main project needs special configuration - they need be hooked-up also.
+
+In implicit configuration detection does not work & to create a mock configuration for all projects - use [implicit-hie](https://github.com/Avi-D-coder/implicit-hie) generator directly to put configuration explicitly - it would add configuarations for all projects at once by:
+```shell
+gen-hie > hie.yaml  # into the main HLS directory
+```
+that configuration now can be inspected, it may work out of the box or can be tuned further with custom configuration.
+
+[Configuring project build](../configuration.md#configuring-your-project-build) applies to HLS project source code loading just as to any other.
+
+Note: HLS implicitly can detect HLS codebase as a Stack project (see [hie-bios implicit configuration documentation](https://github.com/haskell/hie-bios/blob/master/README.md#implicit-configuration)).
+If you want HLS to use Cabal, try to create an `hie.yaml` file:
 ```yaml
 cradle:
   cabal:
 ```
 
-Also note that many subdirectories of a project are in itself are subprojects, so if you want to work on this part of the code, you may also have to create an `hie.yaml` files where `cabal` files reside.
-
-Frequently [implicit-hie](https://github.com/Avi-D-coder/implicit-hie) project helps by generating configuration for all projects by:
-```shell
-gen-hie > hie.yaml  # into the main HLS directory
-```
-that whould generate 1 file with a tree of configuration for all projects, that configuration may work as is or be tuned further with custom configuration.
 
 ### Manually testing your hacked HLS
 If you want to test HLS while hacking on it, follow the steps below.