added documentation

runtime/help/plugins.md

@@ -486,8 +486,8 @@ The following plugins come pre-installed with micro:
    directory, the diff gutter will show changes with respect to the most
    recent Git commit rather than the diff since opening the file.
 
-See `> help linter`, `> help comment`, and `> help status` for additional
-documentation specific to those plugins.
+See `> help autoclose`, `> help linter`, `> help comment`, and `> help status`
+for additional documentation specific to those plugins.
 
 These are good examples for many use-cases if you are looking to write
 your own plugins.

runtime/plugins/autoclose/autoclose.lua

@@ -6,6 +6,7 @@ local utf8 = import("utf8")
 
 config.RegisterCommonOption("autoclose", "pairs", {"\"\"", "''", "``", "()", "{}", "[]"})
 config.RegisterCommonOption("autoclose", "newlinePairs", {"()", "{}", "[]"})
+config.AddRuntimeFile("autoclose", config.RTHelp, "help/autoclose.md")
 
 function charAt(str, i)
     -- lua indexing is one off from go

runtime/plugins/autoclose/help/autoclose.md

@@ -0,0 +1,13 @@
+# Autoclose
+
+The autoclose plugin automatically closes brackets, quotes and the like,
+and it can add indentation between such symbols. The plugin can be configured
+on a per-buffer basis via the following options:
+
+- `autoclose.pairs`: When the first rune in a pair is entered, autoclose will
+  add the second automatically. Moreover, when the first rune is deleted while
+  the cursor is on the second, then this second rune is also deleted.
+  The default value is ```{"\"\"", "''", "``", "()", "{}", "[]"}```.
+- `autoclose.newlinePairs`: When `Enter` is pressed between such a pair,
+  autoclose will put the closing rune on a separate line and add indentation.
+  The default value is `{"()", "{}", "[]"}`.