Remove obsolite configuration instructions

Neither intellij-idea nor eclipse support dotty as it is described on
the pages from the documentation website so this patch removes them from
the website.

Signed-off-by: Nikita Eshkeev <kastolom@gmail.com>

Author: neshkeev

docs/docs/contributing/tools/eclipse.md

@@ -3,9 +3,8 @@ layout: doc-page
 title: Workflow
 ---
 
-Check [Getting Started](getting-started.md) for instructions on how to obtain the source code of dotty and 
-[Eclipse](tools/eclipse.md) or [IntelliJ-IDEA](tools/intellij-idea.md).
-This document details common workflow patterns when working with Dotty before using the debugging tools.
+Check [Getting Started](getting-started.md) for instructions on how to obtain the source code of dotty.
+This document details common workflow patterns when working with Dotty.
 
 ## Compiling files with dotc ##
 

docs/docs/contributing/tools/intellij-idea.md

@@ -185,10 +185,6 @@ sidebar:
           url: docs/contributing/debugging.html
         - title: IDEs and Tools
           subsection:
-            - title: Eclipse
-              url: docs/contributing/tools/eclipse.html
-            - title: IntelliJ IDEA
-              url: docs/contributing/tools/intellij-idea.html
             - title: Mill
               url: docs/contributing/tools/mill.html
             - title: Scalafix