[doc] tuning a few things in documentation.

docs/guide/environment.rst

@@ -1,5 +1,5 @@
 Environment Variables
-=======================
+=====================
 
 Best practice holds that variables should be passed to graphs via environment variables.
 Doing this is important for keeping sensitive data out of the code - such as an
@@ -10,13 +10,16 @@ are also the means by-which arguments can be passed to graphs.
 
 
 Passing / Setting Environment Variables
-::::::::::::::::::::::::::::::::::::::::::::
+:::::::::::::::::::::::::::::::::::::::
 
 Setting environment variables for your graphs to use can be done in a variety of ways and which one used can vary
 based-upon context. Perhaps the most immediate and simple way to set/override a variable for a given graph is 
 simply to use the optional ``--env`` argument when running bonobo from the shell (bash, command prompt, etc). 
 ``--env`` (or ``-e`` for short) should then be followed by the variable name and value using the
-syntax ``VAR_NAME=VAR_VALUE``. Multiple environment variables can be passed by using multiple ``--env`` / ``-e`` flags (i.e. ``bonobo run --env FIZZ=buzz ...`` and ``bonobo run --env FIZZ=buzz --env Foo=bar ...``). Additionally, in bash you can also set environment variables by listing those you wish to set before the `bonobo run` command with space separating the key-value pairs (i.e. ``FIZZ=buzz bonobo run ...`` or ``FIZZ=buzz FOO=bar bonobo run ...``). 
+syntax ``VAR_NAME=VAR_VALUE``. Multiple environment variables can be passed by using multiple ``--env`` / ``-e`` flags
+(i.e. ``bonobo run --env FIZZ=buzz ...`` and ``bonobo run --env FIZZ=buzz --env Foo=bar ...``). Additionally, in bash
+you can also set environment variables by listing those you wish to set before the `bonobo run` command with space
+separating the key-value pairs (i.e. ``FIZZ=buzz bonobo run ...`` or ``FIZZ=buzz FOO=bar bonobo run ...``).
 
 The Examples below demonstrate setting one or multiple variables using both of these methods:
 
@@ -28,16 +31,16 @@ The Examples below demonstrate setting one or multiple variables using both of t
     # Using multiple environment variables via -e (env) flag:
     bonobo run csvsanitizer -e SRC_FILE=inventory.txt -e DST_FILE=inventory_processed.csv
     
-    # Using one environment variable in bash (*bash only):
+    # Using one environment variable inline (bash only):
     SECRET_TOKEN=secret123 bonobo run csvsanitizer
 
-    # Using multiple environment variables in bash (*bash only):
+    # Using multiple environment variables inline (bash only):
     SRC_FILE=inventory.txt DST_FILE=inventory_processed.csv bonobo run csvsanitizer
     
 *Though not-yet implemented, the bonobo roadmap includes implementing environment / .env files as well.*
 
 Accessing Environment Variables from within the Graph Context
-:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
 
 Environment variables, whether set globally or only for the scope of the graph,
 can be can be accessed using any of the normal means. It is important to note
@@ -50,26 +53,22 @@ function and used to get data from the database.
 
     import os
 
-    from bonobo import Graph, run
+    import bonobo
+    from bonobo.config import use
 
 
-    def extract():
+    DB_USER = os.getenv('DB_USER')
-        database_user = os.getenv('DB_USER')
+    DB_PASS = os.getenv('DB_PASS')
-        database_password = os.getenv('DB_PASS')
-        # ...
-        # (connect to database using database_user and database_password)
-        # (get data from database)
-        # ...
-
-        return database_data
 
 
-    def load(database_data: dict):
+    @use('database')
-        for k, v in database_data.items():
+    def extract(database):
-            print('{key} = {value}'.format(key=k, value=v))
+        with database.connect(DB_USER, DB_PASS) as conn:
+            yield from conn.query_all()
 
 
-    graph = Graph(extract, load)
+    graph = bonobo.Graph(
+        extract,
+        bonobo.PrettyPrinter(),
+    )
 
-    if __name__ == '__main__':
-        run(graph)

docs/guide/index.rst

@@ -12,7 +12,7 @@ There are a few things that you should know while writing transformations graphs
     purity
     transformations
     services
-    envrionment_variables
+    envrionment
 
 Third party integrations
 ::::::::::::::::::::::::

docs/reference/api_util.rst

@@ -0,0 +1,10 @@
+Util API
+========
+
+The Util API, located under the :mod:`bonobo.util` namespace, contains helpers functions and decorators to work with
+and inspect transformations, graphs, and nodes.
+
+.. automodule:: bonobo.util
+    :members:
+    :undoc-members:
+    :show-inheritance:

docs/reference/index.rst

@@ -9,6 +9,7 @@ means that the api is not yet 1.0-proof.
 
     api
     api_config
+    api_util
     commands
     settings
     examples

docs/reference/settings.rst

@@ -3,7 +3,8 @@ Settings & Environment
 
 .. module:: bonobo.settings
 
-All settings that you can find in the :module:`bonobo.settings` module.
+All settings that you can find in the :mod:`bonobo.settings` module. You can override those settings using
+environment variables. For you own settings and configuration values, see the :doc:`/guide/environment` guide.
 
 Debug
 :::::