Remove duplicated item

Author: phil-opp

content/this-month/2021-09/index.md

@@ -45,7 +45,6 @@ It is now part of a workspace and lives next to the new crate `multiboot2-header
 The following changes were merged this month:
 
 - [Code style improvements + optional CI job (clippy, rustfmt, rustdoc)](https://github.com/rust-osdev/multiboot2/pull/92)
-- [editorconfig file](https://github.com/rust-osdev/multiboot2/pull/93)
 - [std in tests; hash for TagType](https://github.com/rust-osdev/multiboot2/pull/94) 
 - [editorconfig file](https://github.com/rust-osdev/multiboot2/pull/93)
 - [prepared cargo workspace, as discussed in PR #79](https://github.com/rust-osdev/multiboot2/pull/86)
@@ -54,11 +53,13 @@ The changes were published as <span class="gray">`v0.12.2`</span>.
 
 
 ### [`multboot2-header`](https://github.com/rust-osdev/multiboot2) (**new**)
+
 The `multiboot2-header` crate provides abstraction types for the Multiboot2 header 
 and a builder struct to construct these headers. The corresponding repository was 
 prepared ([#86](https://github.com/rust-osdev/multiboot2/pull/86)) and the initial release 
 is expected in early October. See [#95](https://github.com/rust-osdev/multiboot2/pull/95) for more details.
 
+
 ## Call for Participation
 
 Want to contribute to a Rust OSDev project, but don't know where to start? Pick up one of these outstanding