fix the TOC in the README (#51)

this removes the `[toc]` that have been introduced in the TOC of the
README in #26

README.md

@@ -4,12 +4,12 @@ A collection of Nushell tools to manage `git` repositories.
 # Table of content
 - [nu-git-manager](#nu-git-manager)
 - [Table of content](#table-of-content)
-  - [:bulb: what is `nu-git-manager` \[toc\]](#bulb-what-is-nu-git-manager-toc)
-  - [:link: requirements \[toc\]](#link-requirements-toc)
-  - [:recycle: installation \[toc\]](#recycle-installation-toc)
-  - [:gear: usage \[toc\]](#gear-usage-toc)
-    - [:pray: getting help \[toc\]](#pray-getting-help-toc)
-  - [:exclamation: some ideas of advanced (?) usage \[toc\]](#exclamation-some-ideas-of-advanced--usage-toc)
+  - [:bulb: what is `nu-git-manager`](#bulb-what-is-nu-git-manager-toc)
+  - [:link: requirements](#link-requirements-toc)
+  - [:recycle: installation](#recycle-installation-toc)
+  - [:gear: usage](#gear-usage-toc)
+    - [:pray: getting help](#pray-getting-help-toc)
+  - [:exclamation: some ideas of advanced (?) usage](#exclamation-some-ideas-of-advanced--usage-toc)
 
 ## :bulb: what is `nu-git-manager` [[toc](#table-of-content)]
 like [`ghq`](https://github.com/x-motemen/ghq), `nu-git-manager` aims at being a fully-featured