Order of arguments good practise (#3760)

* Order of arguments good practise

* Add also note about using = when adding values to named args

* Rewording

Author: AbrilRBS

knowledge/guidelines.rst

@@ -43,6 +43,10 @@ Good practices
   the graph to avoid the conflicts without overrides and forces is the recommended approach.
 - **Please, do not abuse 'tool_requires'**. Those are intended only for executables like ``cmake`` and ``ninja`` running in the "build"
   context, not for libraries or library-like dependencies, that must use ``requires`` or ``test_requires``.
+- Positional arguments when invoking Conan should be specified first, before any named argument. For example,
+  ``conan install . -s="os=Windows"`` is correct, but ``conan install -s="os=Windows" .`` is not.
+  Likewise, it's recommended to use ``=`` instead of spaces between the name and value of named arguments.
+  This is to avoid some ambiguity scenarios when parsing the command line arguments.
 
 Forbidden practices
 -------------------