docs: add upgrade/release notes for 1.13.0 (#13394)

* docs: add upgrade/release notes for 1.13.0

* docs: add upgrade/release notes for 1.13.0

website/content/docs/release-notes/v1_13.mdx

@@ -0,0 +1,57 @@
+---
+page_title: Packer v1.13 release notes
+description: Learn about the changes in Packer v 1.13
+---
+
+# Packer v1.13 release notes
+
+This page describes changes to Packer in v1.13. Refer to the [Packer repository](https://github.com/hashicorp/packer/releases) for information about all releases.
+
+## New features
+
+This release includes the following updates.
+
+### Shell Provisioner Enhancement
+
+The shell provisioner’s inline field now supports executing scripts directly, including those with their own shebang (#!) lines.
+This enhancement allows you to provide a full script as an inline command, enabling dynamic scripts via tools like templatefile.
+
+### New functions
+
+As part of Packer 1.13, we have introduced below functions.
+
+* `sum`: takes a list or set of numbers and returns the sum of those numbers..
+* `startswith`: takes two values: a string to check and a prefix string. The function returns true if the string begins with that exact prefix.
+* `endswith`: takes two values: a string to check and a suffix string. The function returns true if the first string ends with that exact suffix.
+
+### Packer fmt command to format multiple HCL files
+
+Added the ability for the packer fmt command to format multiple HCL files at once.
+This enhancement allows users to format several files in a single command invocation.
+
+### Top-Level hcp_packer_registry Block Support
+
+Added support for defining the hcp_packer_registry block at the top level of the Packer configuration. Enables improved management and referencing of HCP Packer registries directly in the root schema.
+Also added validation around the multiple hcp_packer_registry blocks at top level.
+
+## Bug fixes
+
+### Documentation Update
+
+Updated the documentation to explicitly state that a trailing slash is required when uploading directories, regardless of the guest OS.
+This clarification is intended to ensure consistent behavior and prevent confusion, especially for Windows users.
+
+### --use-sequential-evaluation Flag Now Works in Packer Console
+
+Fixed an issue where using the --use-sequential-evaluation flag with packer console resulted in an error.
+The flag is now properly included in the supported options for packer console and works as intended.
+Removed this flag from the fix subcommand, where it was not used or required.
+
+### Inline PowerShell Command
+
+Added a wrapper around inline PowerShell commands executed by the provisioner to catch errors and ensure the Packer build fails if any command results in an error.
+
+### Preserve the user-defined order of variable files
+
+Ensures that Packer now preserves the user-defined order of variable files as input by the user.
+This change maintains the intended precedence of variables, honoring the order specified on the command line.

website/content/docs/upgrade/v1_13.mdx

@@ -0,0 +1,48 @@
+---
+page_title: Upgrade to v1.13
+description: Learn how to upgrade your Packer installation to v1.13
+---
+
+# Upgrade to v1.13
+
+The topic describes upgrade considerations for Packer v1.13. Refer to the [v1.13 release notes](/packer/docs/release-notes/v1_13) for details about changes in v1.13.
+
+## Overview
+
+You can use the upgrade command for the package manager you installed Packer with or download and replace the existing binary to upgrade Packer. Refer to [Install Packer](https://developer.hashicorp.com/packer/install) for instructions.
+
+## Upgrade from 1.12
+
+Packer 1.13's notable changes can be summarised by the following points:
+
+1. Provisioner Enhancement
+2. New functions Support
+3. Packer fmt command to format multiple HCL files
+4. Top-Level hcp_packer_registry Block Support
+
+**Note**: The Powershell provisioner changes are breaking changes.
+
+## Provisioner Enhancement
+
+The `shell` provisioner’s inline field now supports executing scripts directly, including those with their own shebang (#!) lines.
+This enhancement allows you to provide a full script as an inline command, enabling dynamic scripts via tools like templatefile.
+
+Added a wrapper around inline `PowerShell` commands executed by the provisioner to catch errors and ensure the Packer build fails if any command results in an error.
+
+## New functions Support
+
+As part of Packer 1.13, we have introduced more functions.
+
+* `sum`: takes a list or set of numbers and returns the sum of those numbers..
+* `startswith`: takes two values: a string to check and a prefix string. The function returns true if the string begins with that exact prefix.
+* `endswith`: takes two values: a string to check and a suffix string. The function returns true if the first string ends with that exact suffix.
+
+## Packer fmt command to format multiple HCL files
+
+Added the ability for the packer fmt command to format multiple HCL files at once.
+
+## Top-Level hcp_packer_registry Block Support
+
+Added support for defining the `hcp_packer_registry` block at the top level of the Packer configuration. Enables improved management and referencing of HCP Packer registries directly in the root schema.
+
+

website/data/docs-nav-data.json

@@ -906,6 +906,10 @@
       {
         "title": "v1.12",
         "path": "release-notes/v1_12"
+      },
+      {
+        "title": "v1.13",
+        "path": "release-notes/v1_13"
       }
     ]
   },
@@ -919,6 +923,10 @@
       {
         "title": "Upgrade to v1.12",
         "path": "upgrade/v1_12"
+      },
+      {
+        "title": "Upgrade to v1.13",
+        "path": "upgrade/v1_13"
       }
     ]
   },