add documentation

docs/configs/introduction.rst

@@ -6,35 +6,33 @@ This document provides an overview of the configuration to provide to
 the :ref:`anemoi-inference run <run-cli>` command line tool.
 
 The configuration file is a YAML file that specifies various options. It
-is composed of :ref:`top level <top-level>` options which are usially
+is composed of :ref:`top level <top-level>` options which are usually
 simple values such as strings, number or booleans. The configuration
 also provide ways to specify which internal classes to use for the
 :ref:`inputs <inputs>` and :ref:`outputs <outputs>`, and how to
 configure them.
 
-In that case, the configuration as the format as show below. The key
-``kind`` corresponds to and underlying Python class that will be used to
-process the input, output or any other polymorphic behaviour.
+In that case, the general format is shown below. The first entry
+(``mars`` or ``grib`` in the examples below) corresponds to the
+underlying Python class that will be used to process the input, output
+or any other polymorphic behaviour, followed by arguments specific to
+that class.
 
 .. literalinclude:: introduction_1.yaml
    :language: yaml
 
-If the underlying class does not require any arguments, or you wish to
-use the default parameters, you can use the following format:
+or:
 
 .. literalinclude:: introduction_2.yaml
    :language: yaml
 
-For example, the following configuration specifies the use of the
-``grib`` input class, from which to read the initial conditions, and the
-``printer`` output class, which prints the minimum and maximum values of
-a few fields at each forecasting time step.
+If the underlying class does not require any arguments, or you wish to
+use the default parameters, then configuration can be simplified as:
 
 .. literalinclude:: introduction_3.yaml
    :language: yaml
 
-When a class has a single argument you can ommite the key and directly
-provide the value. The previous example can be simplified as:
+or if it expects a single argument, it can be simplified as:
 
 .. literalinclude:: introduction_4.yaml
    :language: yaml

docs/configs/introduction_1.yaml

@@ -1,5 +1,4 @@
 input:
-  kind:
-    param1: value1
-    param2: value2
-    ...: ...
+  mars:
+    class: ea
+    stream: oper

docs/configs/introduction_2.yaml

@@ -1 +1,3 @@
-input: kind
+input:
+  grib:
+    path: /path/to/grib/file.grib

docs/configs/introduction_3.yaml

@@ -1,5 +1 @@
-input:
-  grib:
-    path: /path/to/grib/file.grib
-
-output: printer
+input: mars

docs/configs/introduction_4.yaml

@@ -1,4 +1,2 @@
 input:
   grib: /path/to/grib/file.grib
-
-output: printer

docs/configs/introduction_5.yaml

@@ -0,0 +1,4 @@
+input:
+  grib: /path/to/grib/file.grib
+
+output: printer