Rename migrationsDir sqlDir.

README.md

@@ -1,4 +1,36 @@
-DB Migrate
-==========
+# DB Migrate
 
 Small tool(s) to manage database migrations in various languages.
+
+## Usage
+
+```
+Usage:
+  db_migrate [options] create <migration-name>
+  db_migrate [options] up [<count>]
+  db_migrate [options] down [<count>]
+  db_migrate [options] init <schema-name>
+  db_migrate (-V | --version)
+  db_migrate (-h | --help)
+
+Options:
+  -c --config <config-file>   Use the given configuration file (defaults to
+                              "database.properties").
+  -q --quiet                  Suppress log information.
+  -v --verbose                Print detailed log information.
+     --very-verbose           Print very detailed log information.
+  -V --version                Print the tools version information.
+  -h --help                   Print this usage information.
+```
+
+
+## Database Config Format
+
+The database config is formatted as JSON. The following keys are supported by
+all of the implementations:
+
+* `sqlDir` -- Directory to store SQL files.
+
+The following keys are supported by the Nim implementation:
+
+* `connectionString` --