Add usage information to README.

README.md

@@ -1,11 +1,139 @@
-# Menu Helper
+# Menu-Helper
 
 A program to manage a database of recipes and help you to pick out meals based
 on filters of ingredients and tags.
 
 ## Usage
 
-Ensure the `XDG_DATA_HOME` variable is set (e.g. to `$HOME/.local/share`).
+Ensure the `XDG_DATA_HOME` variable is set (e.g. to `$HOME/.local/share`) and
+that you have installed the SQLite3 library.
+
+Upon first execution of any command, the program will automatically create the
+database.
+
+### Adding New Recipes
+
+The first thing you're probably going to want to do is to add a new recipe to
+your database. If this database hasn't been created already then the program
+will do it automatically. This is done via the `add` subcommand, which will
+query you about the different attributes you want for your recipe, looking
+something like the following:
+
+```console
+$ menu-helper add
+Name: Linguine Scampi
+Description: A lemony Italian pasta dish.
+Ingredients (comma separated): linguine,shrimp,garlic,parsley,lemon
+Tags (comma separated): italian,lunch
+Creating database in /home/nicolas/.local/share/menu-helper/recipes.db
+```
+
+This will have created your recipe within the database. That last line there is
+merely informative, telling you that the database did not exist and it is not
+being created; if you had a database already and it isn't being found, ensure
+that your `XDG_DATA_HOME` environment variable is properly set.
+
+### Querying Recipes
+
+#### Filtering
+
+Once a recipe or two have been added to your database you may now query them
+filtering based on ingredients and tags. This is done via the `list` command,
+which takes two kinds of arguments, both optional:
+
+- `-i <list>`: Comma-separated list of the ingredients to look for.
+- `-t <list>`: Comma-separated list of the tags to look for.
+
+If neither is specified then all recipes will be listed with their respective
+ID, name, and description:
+
+```console
+$ menu-helper list
+1  |  Linguine Scampi  |  A lemony Italian pasta dish.
+2  |  Garlic Soup  |  A simple monastic soup for cold winters.
+```
+
+However, when one of these arguments is used it filters recipes to only show
+those which include __all__ the ingredients and tags specified:
+
+```console
+$ menu-helper list -i linguine
+1  |  Linguine Scampi  |  A lemony Italian pasta dish.
+```
+
+#### Recipe Information
+
+The IDs shown in the queries above now become useful for the rest of
+Menu-Helper functionality. If you wish to query all stored information about a
+given recipe, this is where you can use the `info` subcommand with the relevant
+ID:
+
+```console
+$ menu-helper info 2
+Name: Garlic Soup
+Description: A simple monastic soup for cold winters.
+ID: 2
+
+Ingredients:
+        - garlic
+        - bread
+        - egg
+
+Tags:
+        - soup
+        - dinner
+        - simple
+
+```
+
+### Removing Recipes
+
+If you end up desiring to remove a recipe for whatever reason, you can do so by
+using the `del` subcommand with the recipe's corresponding ID:
+
+```console
+$ menu-helper del 2
+$ menu-helper list
+1  |  Linguine Scampi  |  A lemony Italian pasta dish.
+```
+
+### Modifying Recipe Ingredients/Tags
+
+If there are ingredients/tags which you forgot to add to a recipe, or that you
+added erringly, you can correct this with the following commands:
+
+- `add-ingr <id> <list>`: Add list of comma-separated ingredients `list` to
+  recipe with ID `id`.
+- `rm-ingr <id> <list>`: Remove list of comma-separated ingredients `list` from
+  recipe with ID `id`.
+- `add-tag <id> <list>`: Add list of comma-separated tags `list` to recipe with
+  ID `id`.
+- `rm-tag <id> <list>`: Remove list of comma-separated tags `list` from recipe
+  with ID `id`.
+
+For example, we forgot to add the useful tag to our first recipe (Linguine
+Scampi) that it is a pasta dish. We can do this with the following command:
+
+```console
+$ menu-helper add-tag 1 pasta
+$ menu-helper info 1
+Name: Linguine Scampi
+Description: A lemony Italian pasta dish.
+ID: 1
+
+Ingredients:
+        - linguine
+        - shrimp
+        - garlic
+        - parsley
+        - lemon
+
+Tags:
+        - italian
+        - lunch
+        - pasta
+
+```
 
 ## Building
 
@@ -15,7 +143,9 @@ To build the program you will require the following dependencies:
 - SQLite3 C/C++ library
 - Make
 
-Once installed, compile the project with the `make` command.
+Once installed, compile the project with the `make` command. To install simply
+run the `make install` command, optionally appending `PREFIX=...` to change the
+default directory of installation (i.e. `/usr/local/...`).
 
 ## Contributing