add config

config/source/file/README.md

@@ -0,0 +1,70 @@
+# File Source
+
+The file source reads config from a file. 
+
+It uses the File extension to determine the Format e.g `config.yaml` has the yaml format. 
+It does not make use of encoders or interpet the file data. If a file extension is not present 
+the source Format will default to the Encoder in options.
+
+## Example
+
+A config file format in json
+
+```json
+{
+    "hosts": {
+        "database": {
+            "address": "10.0.0.1",
+            "port": 3306
+        },
+        "cache": {
+            "address": "10.0.0.2",
+            "port": 6379
+        }
+    }
+}
+```
+
+## New Source
+
+Specify file source with path to file. Path is optional and will default to `config.json`
+
+```go
+fileSource := file.NewSource(
+	file.WithPath("/tmp/config.json"),
+)
+```
+
+## File Format
+
+To load different file formats e.g yaml, toml, xml simply specify them with their extension
+
+```
+fileSource := file.NewSource(
+        file.WithPath("/tmp/config.yaml"),
+)
+```
+
+If you want to specify a file without extension, ensure you set the encoder to the same format
+
+```
+e := toml.NewEncoder()
+
+fileSource := file.NewSource(
+        file.WithPath("/tmp/config"),
+	source.WithEncoder(e),
+)
+```
+
+## Load Source
+
+Load the source into config
+
+```go
+// Create new config
+conf := config.NewConfig()
+
+// Load file source
+conf.Load(fileSource)
+```
+