update readme

README.md

@@ -42,8 +42,9 @@ Configure `java-dotenv` once in your application.
 ```kotlin
 val dotenv = Dotenv
  .configure()
- .directory("./src/test/resources")
- .ignoreIfMalformed()
+ .directory("./") // set to the current directory
+ .ignoreIfMalformed() // do not throw an error if .env is malformed
+ .ignoreIfMissing() // do not throw an error if .env is missing
  .build()
 ```
 
@@ -74,6 +75,19 @@ Note, environment variables specified in `.env` take precedence over those confi
 dotenv.get("MY_ENV_VAR1");
 ```
 
+## Configuration options
+
+### *required* `directory(path: String)` 
+`path` specifies the directory containing `.env`. Dotenv first searches for `.env` using the given path on the filesystem. If not found it searches the given path on the classpath.
+
+### *optional* `ignoreIfMalformed()`
+
+Do not throw when `.env` entries are malformed. Malformed entries are skipped.
+
+### *optional* `ignoreIfMissing()` 
+
+Do not throw when `.env` does not exist. Dotenv will continue to retrieve environment variables that are set in the environment e.g. `dotenv["HOME"]`
+
 ## License
 
 [Apache 2.0](https://www.apache.org/licenses/LICENSE-2.0)