docs: improve make example docs and add proxmox setup how-to (#829)

* docs: improve make example documentation, add how-to for proxmox setup

Signed-off-by: rafsaf <rafal.safin12@gmail.com>

* docs: revert unwanted styling changes in pull request template file

Signed-off-by: rafsaf <rafal.safin12@gmail.com>

---------

Signed-off-by: rafsaf <rafal.safin12@gmail.com>

.github/PULL_REQUEST_TEMPLATE.md

@@ -9,6 +9,8 @@ Leave the [ ] if they are not applicable, or if you have not completed the item.
 
 <!---
 You can find more information about coding conventions and local testing in the [CONTRIBUTING.md](https://github.com/bpg/terraform-provider-proxmox/blob/main/CONTRIBUTING.md) file.
+
+If you are unsure how to run `make example`, see [Deploying the example resources](https://github.com/bpg/terraform-provider-proxmox?tab=readme-ov-file#deploying-the-example-resources) section in README.
 --->
 
 <!--

README.md

@@ -62,7 +62,7 @@ environment. The following assumptions are made about the test environment:
 - The node has local storages named `local` and `local-lvm`
 - The "Snippets" content type is enabled in `local` storage
 
-Create `examples/terraform.tfvars` with the following variables:
+Create `example/terraform.tfvars` with the following variables:
 
 ```sh
 virtual_environment_username = "root@pam"
@@ -72,6 +72,8 @@ virtual_environment_endpoint = "https://<your-cluster-endpoint>:8006/"
 
 Then run `make example` to deploy the example resources.
 
+If you don't have free proxmox cluster to play with, there is dedicated [how-to tutorial](howtos/setup-proxmox-for-make-example/README.md) how to setup Proxmox inside VM and run `make example` on it.
+
 ## Future work
 
 The provider is using

howtos/README.md

@@ -6,3 +6,7 @@ A collection of HOW-TOs for common tasks.
 
 - [Create a VM from a Cloud Image](howtos/cloud-image/README.md)
 - [Configure a VM with Cloud-Init](howtos/cloud-init/README.md)
+
+## Contributors
+
+- [Setup VM with proxmox to run make example](howtos/setup-proxmox-for-make-example/README.md)

howtos/setup-proxmox-for-make-example/README.md

@@ -0,0 +1,87 @@
+# Setup VM with proxmox to run make example
+
+## Who
+
+Contributors
+
+## Motivation
+
+To test changes, it's best to try it on real proxmox cluster. There is dedicated `make example` command that will try to apply changes defined in `example` directory. Most resources have its examples declarations there. For example, if you add new resource, you could add new file with example resource there (ideally after adding tests). If nothing breaks, apply works fine, new resource is created and all other resources are fine, then likely change is safe.
+
+But – proxmox node setup can be tricky task for some contributors.
+
+## Preconditions
+
+Be sure to install `go` and `terraform` on your system first.
+
+## Linux (Debian/Ubuntu) with virt-manager
+
+Goal is to have a proxmox node in VM using https://virt-manager.org/ for a job. This text assumes some linux knowledge. Tested on Debian 12 bookworm and proxmox VE 8.1. For other distros, with any luck steps should be similar.
+
+1. `sudo apt-get install virt-manager`.
+
+2. Download some proxmox image from http://download.proxmox.com/iso/, currently latest is `proxmox-ve_8.1-1.iso`.
+
+3. Run `virt-manager` and "create a new virtual machine", use a file you just downloaded, choose debian as a operating system, leave default network settings.
+
+4. Give it enough RAM and disk size (required minimum is unknown for make example though I used 4GB on my 8GB laptop and 30GB disk size with success).
+
+5. Proceed forward with installation, choose whatever you want for timezone, country, password, domain, email. Don't change other default settings.
+
+6. After installation, log in using password from previous step and `root` username (it's proxmox default). Run: `ip a` to get assigned ip (this also appears during installation). In my case it is `192.168.122.43`.
+
+   It may look like this:
+
+   ```
+   root@proxmox:~# ip a
+   1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
+       link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
+       inet 127.0.0.1/8 scope host lo
+       valid_lft forever preferred_lft forever
+       inet6 ::1/128 scope host noprefixroute
+       valid_lft forever preferred_lft forever
+   2: enp1s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master vmbr0 state UP group default qlen 1000
+       link/ether 52:54:00:b3:22:f5 brd ff:ff:ff:ff:ff:ff
+   3: vmbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
+       link/ether 52:54:00:b3:22:f5 brd ff:ff:ff:ff:ff:ff
+       inet 192.168.122.43/24 scope global vmbr0
+       valid_lft forever preferred_lft forever
+       inet6 fe80::5054:ff:feb3:22f5/64 scope link
+       valid_lft forever preferred_lft forever
+   ```
+
+7. (Optional) On **your** computer, there should be new interface created mapped to that one you see on proxmox. Again `ip a`:
+
+   ```
+   ...
+
+   8: virbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
+       link/ether 52:54:00:ca:65:49 brd ff:ff:ff:ff:ff:ff
+       inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
+       valid_lft forever preferred_lft forever
+
+   ...
+
+   ```
+
+8. (Optional) You can SSH into proxmox node:
+
+   ```bash
+   ssh root@192.168.122.43
+   ```
+
+   You can also use browser and visit console at https://192.168.122.43:8006.
+
+9. Create `terraform.tfvars` file (it will be git ignored file) in `example` folder with credentials for you new proxmox node.
+
+   ```
+   # example/terraform.tfvars
+   virtual_environment_username = "root@pam"
+   virtual_environment_endpoint = "https://192.168.122.43:8006/"
+   virtual_environment_password = "your password from step 5"
+
+   ```
+
+10. Now you can run `make example`.
+
+11. If you see error with proxmox_virtual_environment_file: the datastore "local" does not support content type "snippets"; supported content types are: [backup iso vztmpl], you need to enable them, see https://registry.terraform.io/providers/bpg/proxmox/latest/docs/resources/virtual_environment_file#snippets.