Revert all README changes - I will put them back later.

Author: nedtwigg

README.md

@@ -53,7 +53,6 @@ lib('npm.TsFmtFormatterStep')                    +'{{yes}}       | {{yes}}
 lib('scala.ScalaFmtStep')                        +'{{yes}}       | {{yes}}       | {{no}}  |',
 lib('sql.DBeaverSQLFormatterStep')               +'{{yes}}       | {{no}}       | {{no}}  |',
 extra('wtp.EclipseWtpFormatterStep')             +'{{yes}}       | {{yes}}      | {{no}}  |',
-lib('antlr4.Antlr4FormatterStep')                +'{{yes}}       | {{yes}}       | {{no}}  |',
 '| [(Your FormatterStep here)](CONTRIBUTING.md#how-to-add-a-new-formatterstep) | {{no}}        | {{no}}       | {{no}}  |',
 '| Fast up-to-date checking                      | {{yes}}       | {{no}}       | {{no}}  |',
 '| Automatic idempotency safeguard               | {{yes}}       | {{no}}       | {{no}}  |',
@@ -82,7 +81,6 @@ lib('antlr4.Antlr4FormatterStep')                +'{{yes}}       | {{yes}}
 | [`scala.ScalaFmtStep`](lib/src/main/java/com/diffplug/spotless/scala/ScalaFmtStep.java) | :+1:       | :+1:       | :white_large_square:  |
 | [`sql.DBeaverSQLFormatterStep`](lib/src/main/java/com/diffplug/spotless/sql/DBeaverSQLFormatterStep.java) | :+1:       | :white_large_square:       | :white_large_square:  |
 | [`wtp.EclipseWtpFormatterStep`](lib-extra/src/main/java/com/diffplug/spotless/extra/wtp/EclipseWtpFormatterStep.java) | :+1:       | :+1:      | :white_large_square:  |
-| [`antlr4.Antlr4FormatterStep`](lib/src/main/java/com/diffplug/spotless/antlr4/Antlr4FormatterStep.java) | :+1:       | :+1:       | :white_large_square:  |
 | [(Your FormatterStep here)](CONTRIBUTING.md#how-to-add-a-new-formatterstep) | :white_large_square:        | :white_large_square:       | :white_large_square:  |
 | Fast up-to-date checking                      | :+1:       | :white_large_square:       | :white_large_square:  |
 | Automatic idempotency safeguard               | :+1:       | :white_large_square:       | :white_large_square:  |

plugin-gradle/README.md

@@ -94,7 +94,6 @@ Spotless can check and apply formatting to any plain-text file, using simple rul
 * [DBeaver sql format](https://dbeaver.jkiss.org/)
 * [Prettier: An opinionated code formatter](https://prettier.io)
 * [TypeScript Formatter (tsfmt)](https://github.com/vvakame/typescript-formatter)
-* [Antlr4Formatter](https://github.com/antlr/Antlr4Formatter)
 * Any user-defined function which takes an unformatted string and outputs a formatted version.
 
 Contributions are welcome, see [the contributing guide](../CONTRIBUTING.md) for development info.
@@ -569,25 +568,6 @@ Unlike Eclipse, Spotless WTP ignores per default external URIs in schema locatio
 external entities. To allow the access of external URIs, set the property `resolveExternalURI`
 to true.
 
-<a name="antlr4"></a>
-
-## Applying to ANTLR4 source
-
-By default, all ANTLR4 sources matching `src/main/antlr4/**/*.g4` or `src/test/antlr4/**/*.g4` will be formatted. To change this,
-set the `target` parameter as described in the [Custom rules](#custom) section.
-
-```gradle
-spotless {
-  antlr4 {
-    // use default Antlr4Formatter version
-    antlr4Formatter()
-
-    // specify a custom Antlr4Formatter version
-    antlr4Formatter('1.2.1')
-  }
-}
-```
-
 <a name="license-header"></a>
 
 ## License header options

plugin-maven/README.md

@@ -78,7 +78,6 @@ Spotless supports the following powerful formatters:
 * Google's [google-java-format](https://github.com/google/google-java-format)
 * [Typescript Tsfmt formatter](https://github.com/vvakame/typescript-formatter)
 * [Prettier formatter](https://prettier.io)
-* [Antlr4Formatter](https://github.com/antlr/Antlr4Formatter)
 * User-defined license enforcement, regex replacement, etc.
 
 Contributions are welcome, see [the contributing guide](../CONTRIBUTING.md) for development info.
@@ -218,26 +217,6 @@ By default, all files matching `src/main/cpp/**/*.<ext>` and `src/test/cpp/**/*.
 ```
 Use the Eclipse to define the *Code Style preferences* (see [Eclipse documentation](https://www.eclipse.org/documentation/)). Within the preferences *Edit...* dialog, you can export your configuration as XML file, which can be used as a configuration `<file>`. If no `<file>` is provided, the CDT default configuration is used.
 
-<a name="antlr4"></a>
-## Applying to ANTLR4 source
-
-By default, all ANTLR4 sources matching `src/main/antlr4/**/*.g4` or `src/test/antlr4/**/*.g4` will be formatted. To change this,
-set the `includes` parameter as described in the [File incudes and excludes](#includeExclude) section.
-
-```xml
-<configuration>
-  <antlr4>
-    <!-- use default Antlr4Formatter version -->
-    <antlr4Formatter />
-
-    <antlr4Formatter>
-      <!-- specify a custom Antlr4Formatter version -->
-      <version>1.2.1</version>
-    </antlr4Formatter>
-  </antlr4>
-</configuration>
-```
-
 <a name="typescript"></a>
 
 ## Applying to Typescript source