docs: tutorial for bash autocomplete (#24398)

* including tutorial for bash autocomplete

- included the Bash Autocomplete in sidebar.yml
- created a new file called Bash-Autocomplete.md with a tutorial to include a bash autocomplete.
This tutorial was based on:
	- https://github.com/urfave/cli/blob/master/docs/v1/manual.md#enabling
	- https://github.com/urfave/cli/blob/master/docs/v2/manual.md#powershell-support

* Update docs/_interface/Bash-Autocomplete.md

- From "Creates" to "Create" in Windows tutorial

Co-authored-by: ligi <ligi@ligi.de>

* Update docs/_interface/Bash-Autocomplete.md

- From "Creates" to "Create" in Linux/MacOS tutorial

Co-authored-by: ligi <ligi@ligi.de>

* (_layouts): redirect to first element in documentation

- Problem: The sidebar was redirecting to the wrong element
in the list when we click on that. It was occuring because the logic inside of sidebar.html
to build the list-group-item was carry about the frontdoc.url instead of the first element by itself.

- Solution: We are sorting the collection.docs and then build the
list-group-item with the right element in the list.

Co-authored-by: ligi <ligi@ligi.de>

_data/sidebar.yml

@@ -10,6 +10,7 @@ How to use:
   - Contract Tutorial: /docs/Contract-Tutorial
 Interface Documentation:
   - Command Line Options: /docs/Command-Line-Options
+  - Bash Autocomplete: /docs/Bash-Autocomplete
   - JavaScript Console: /docs/JavaScript-Console
   - Management API: /docs/Management-APIs
   - JSON-RPC server: https://github.com/ethereum/wiki/wiki/JSON-RPC

_layouts/sidebar.html

@@ -11,11 +11,10 @@ layout: default
       {% unless frontdoc %}
         {% assign frontdoc = collection.docs[0] %}
       {% endunless %}
-      {% capture target %}{% include link.html url=frontdoc.url %}{% endcapture %}
+      {% assign docs_by_sort_key = collection.docs | group_by:"sort_key" | sort:"name", "last" %}
       <div class="list-group">
-        <a class="list-group-item active" href="{{ target |strip }}">{{ collection.caption }}</a>
+        <a class="list-group-item active" href="{{ docs_by_sort_key[0].items[0].url }}">{{ collection.caption }}</a>
         {% if page.collection == collection.label  %}
-          {% assign docs_by_sort_key = collection.docs | group_by:"sort_key" | sort:"name", "last" %}
           {% for group in docs_by_sort_key %}
             {% assign docs_sorted = group.items | sort:"title" %}
             {% for doc in docs_sorted %}

docs/_interface/Bash-Autocomplete.md

@@ -0,0 +1,66 @@
+---
+title: Bash Autocomplete
+sort_key: C
+---
+
+You can enable autocompletion in geth just running a bash script (Linux/MacOS) or a powershell script (Windows).
+
+### Linux/MacOS
+
+1.  Create a bash script file with the content below and save as `geth-autocompletion` anywhere in your computer (i.e. `/bin/geth-autocompletion`):
+
+    ```bash
+    #! /bin/bash
+
+    : ${PROG:=$(basename ${BASH_SOURCE})}
+
+    _cli_bash_autocomplete() {
+    if [[ "${COMP_WORDS[0]}" != "source" ]]; then
+        local cur opts base
+        COMPREPLY=()
+        cur="${COMP_WORDS[COMP_CWORD]}"
+        if [[ "$cur" == "-"* ]]; then
+        opts=$( ${COMP_WORDS[@]:0:$COMP_CWORD} ${cur} --generate-bash-completion )
+        else
+        opts=$( ${COMP_WORDS[@]:0:$COMP_CWORD} --generate-bash-completion )
+        fi
+        COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )
+        return 0
+    fi
+    }
+
+    complete -o bashdefault -o default -o nospace -F _cli_bash_autocomplete $PROG
+    unset PROG
+    ```
+
+2.  Open and edit your **startup script** depending on the terminal in use (i.e. `~/.bashrc` or `~/.zshrc`).
+
+3.  Includes this command in the final of your **startup script**:
+
+    ```bash
+    # i.e. PROG=geth source /bin/geth-autocompletion
+    PROG=geth source /path/to/autocomplete/geth-autocompletion-script
+    ```
+
+### Windows
+
+1.  Create a powershell script file with the content below and save as `geth.ps1` anywhere in your computer.
+
+    ```bash
+    $fn = $($MyInvocation.MyCommand.Name)
+    $name = $fn -replace "(.*)\.ps1$", '$1'
+    Register-ArgumentCompleter -Native -CommandName $name -ScriptBlock {
+        param($commandName, $wordToComplete, $cursorPosition)
+        $other = "$wordToComplete --generate-bash-completion"
+            Invoke-Expression $other | ForEach-Object {
+                [System.Management.Automation.CompletionResult]::new($_, $_, 'ParameterValue', $_)
+            }
+    }
+    ```
+
+2.  Open the PowerShell profile (`code $profile` or `notepad $profile`) and add the line:
+
+    ```bash
+    & path/to/autocomplete/geth.ps1
+    ```
+