update doc

en/_sources/advanced-use.md.txt

@@ -6,6 +6,7 @@ Advanced Usage
 * help - display Arthas help
 * cls - clear the screen
 * [cat](cat.md) - Concatenate and print files
+* [echo](echo.md) - write arguments to the standard output
 * [grep](grep.md) - Pattern searcher
 * [tee](tee.md) - Copies standard input to standard output, making a copy in zero or more files.
 * [pwd](pwd.md) - Return working directory name
@@ -85,6 +86,10 @@ Arthas supports living inside a browser. The communication between arthas and br
 
 * [Web Console](web-console.md)
 
+## Start as a Java Agent
+
+* [Start as a Java Agent](agent.md)
+
 ## User data report
 
 After the `3.1.4` version, arthas support user data report.

en/_sources/agent.md.txt

@@ -0,0 +1,14 @@
+Start as a Java Agent
+====
+
+Usually Arthas dynamic attach the applications on the fly, but from version `3.2.0` onwards, Arthas supports starting directly as a java agent.
+
+For example, download the full arthas zip package, decompress it and start it by specifying `arthas-agent.jar` with the parameter `-javaagent`.
+
+````
+java -javaagent:/tmp/test/arthas-agent.jar -jar arthas-demo.jar
+````
+
+The default configuration is in the `arthas.properties` file in the decompression directory.
+
+Reference: https://docs.oracle.com/javase/8/docs/api/java/lang/instrument/package-summary.html

en/_sources/commands.md.txt

@@ -33,6 +33,7 @@ All Commands
 * [profiler](profiler.md)
 
 * [cat](cat.md)
+* [echo](echo.md)
 * [grep](grep.md)
 * [tee](tee.md)
 * [pwd](pwd.md)

en/_sources/echo.md.txt

@@ -0,0 +1,9 @@
+echo
+===
+
+> write arguments to the standard output.
+
+
+```bash
+$ echo 'hello'
+```

en/_sources/options.md.txt

@@ -10,6 +10,7 @@ options
 | batch-re-transform | true  | whether to re-transform matched classes in batch|
 | json-format        | false | whether to output in JSON format|
 | disable-sub-class  | false | whether to enable matching child classes. The default value is `true`. If exact match is desire, turn off this flag|
+| support-default-method  | true | whether to enable matching default method in interface. The default value is `true`. Refer to [#1105](https://github.com/alibaba/arthas/issues/1105) |
 | debug-for-asm      | false | whether to enable ASM debugging log|
 | save-result        | false | whether to save execution result. All execution results will be saved to `~/logs/arthas-cache/result.log` when it's turned on|
 | job-timeout        | 1d    | default timeout for background jobs. Background job will be terminated once it's timed out (i.e. 1d, 2h, 3m, 25s)| print-parent-fields        | true    | This option enables print files in parent class, default value true.|