remove preface heading from tutorial and get-started pages

The '## Preface' heading served as a meta-label rather than descriptive
content. Removing it allows introductory text to flow naturally after
the frontmatter, following standard documentation conventions.

Also fix MD029 linting issue in grpc-basic-auth.md (code block
indentation within ordered list).

Author: b00f

.mdlrc.rb

@@ -24,5 +24,5 @@
 # First line in file should be a top level header
 exclude_rule 'MD041'
 
+# Allow Multiple headers with the same content
 exclude_rule 'MD024'
-exclude_rule 'MD029'

content/get-started/become-a-validator.md

@@ -13,7 +13,8 @@ they are self-elected through a randomization algorithm based on their stake and
 
 ## What Roles do Validators Play?
 
-Validators can run Pactus Core software on their personal computers or remote servers to process transactions, create blocks,
+Validators can run Pactus Core software on their personal computers or
+remote servers to process transactions, create blocks,
 and uphold network security and decentralization.
 By staking their own coins, validators contribute to the network's security and are rewarded for their efforts.
 

content/get-started/configuration.md

@@ -3,8 +3,6 @@ title: Pactus Node Configuration
 weight: 6
 ---
 
-## Preface
-
 The Pactus node can be configured using a [TOML](https://toml.io/en/) file,
 which is a simple text format for configuration.
 This file is automatically created when the node initializes.

content/get-started/pactus-daemon.md

@@ -3,8 +3,6 @@ title: Run Pactus in Command Line Mode
 weight: 3
 ---
 
-## Preface
-
 Pactus can be run in different modes, including the command-line interface (CLI) and the graphical user interface (GUI).
 This tutorial will guide you through the steps to run Pactus in CLI mode, suitable for advanced users.
 

content/get-started/pactus-docker.md

@@ -3,8 +3,6 @@ title: Run Pactus using Docker
 weight: 4
 ---
 
-## Preface
-
 Docker is a tool that simplifies the process of creating, deploying, and running applications using containers.
 With containers, developers can bundle all the necessary parts of an application, including libraries and dependencies,
 and deploy them as a single package.

content/get-started/pactus-gui.md

@@ -3,8 +3,6 @@ title: Run Pactus in Graphic Mode
 weight: 2
 ---
 
-## Preface
-
 Pactus can be run in different modes, including the command-line interface (CLI) and the graphical user interface (GUI).
 This tutorial will guide you through the steps to run Pactus in GUI mode, suitable for beginner to advanced users.
 

content/tutorials/grpc-basic-auth.md

@@ -3,8 +3,6 @@ title: Secure gRPC Using Basic Authentication
 weight: 6
 ---
 
-## Preface
-
 The Pactus Blockchain offers a gRPC interface, enabling users to interact with the blockchain
 and its native wallet. To enhance the security of gRPC APIs, we have implemented a Basic Authentication
 mechanism based on [bcrypt](https://en.wikipedia.org/wiki/Bcrypt) password hashing.
@@ -77,12 +75,12 @@ To enable Basic Authentication in your Pactus Blockchain configuration, follow t
 1. Open the [configuration](https://docs.pactus.org/get-started/configuration/) file in your Pactus directory.
 2. Insert the generated user with the hashed password into the `basic_auth` field in the `grpc` section:
 
-```toml
-[grpc]
-enable = true
-enable_wallet = false
-listen = "127.0.0.1:50051"
-basic_auth = "user:$2a$10$nl6VKEzSENIK5dmzoADgKeTFtCusQxeVCZiXkRzzbyfG.bLpHtrda"
-```
+   ```toml
+   [grpc]
+   enable = true
+   enable_wallet = false
+   listen = "127.0.0.1:50051"
+   basic_auth = "user:$2a$10$nl6VKEzSENIK5dmzoADgKeTFtCusQxeVCZiXkRzzbyfG.bLpHtrda"
+   ```
 
 3. Restart or run the node to apply this configuration.

content/tutorials/grpc-sign-transactions.md

@@ -3,8 +3,6 @@ title: Sign Transactions Using gRPC
 weight: 5
 ---
 
-## Preface
-
 The Pactus Blockchain provides a gRPC interface that allows users to interact with the blockchain and native wallet.
 This is ideal for merchants and users who want to create, sign, and broadcast transactions using their local node.
 This tutorial will guide you step-by-step on how to use gRPC to sign transactions.

content/tutorials/integration-guide.md

@@ -3,8 +3,6 @@ title: Pactus Integration Guide
 weight: 14
 ---
 
-## Preface
-
 This guide is intended for developers and infrastructure teams who want to connect
 their applications directly to the Pactus network, including wallets, exchanges,
 analytics platforms, staking services, and custom backend systems.

content/tutorials/linux-systemd.md

@@ -3,8 +3,6 @@ title: Run Pactus as a Systemd Service
 weight: 11
 ---
 
-## Preface
-
 [Systemd](https://en.wikipedia.org/wiki/Systemd) is a system and service manager for Linux that
 helps manage how programs start up, run, and shut down.
 It also handles system processes, logging, and basic service monitoring.