docs: Document naming conventions for templates & backend configs (#28924)

* docs: Document naming conventions for templates & backend configs

* Update website/docs/cli/config/config-file.html.md

Co-authored-by: Alisdair McDiarmid <alisdair@users.noreply.github.com>

* Update website/docs/language/functions/templatefile.html.md

Co-authored-by: Alisdair McDiarmid <alisdair@users.noreply.github.com>

Co-authored-by: Alisdair McDiarmid <alisdair@users.noreply.github.com>

website/docs/cli/config/config-file.html.md

@@ -13,10 +13,10 @@ The CLI configuration file configures per-user settings for CLI behaviors,
 which apply across all Terraform working directories. This is separate from
 [your infrastructure configuration](/docs/language/index.html).
 
-## Location
+## Locations
 
-The configuration is placed in a single file whose location depends on the
+The configuration can be placed in a single file whose location depends
-host operating system:
+on the host operating system:
 
 * On Windows, the file must be named `terraform.rc` and placed
   in the relevant user's `%APPDATA%` directory. The physical location
@@ -34,6 +34,7 @@ confirm the filename.
 
 The location of the Terraform CLI configuration file can also be specified
 using the `TF_CLI_CONFIG_FILE` [environment variable](/docs/cli/config/environment-variables.html).
+Any such file should follow the naming pattern `*.tfrc`.
 
 ## Configuration File Syntax
 

website/docs/language/functions/templatefile.html.md

@@ -39,11 +39,16 @@ beginning of a Terraform run. Functions do not participate in the dependency
 graph, so this function cannot be used with files that are generated
 dynamically during a Terraform operation.
 
+`*.tftpl` is the recommended naming pattern to use for your template files.
+Terraform will not prevent you from using other names, but following this
+convention will help your editor understand the content and likely provide
+better editing experience as a result.
+
 ## Examples
 
 ### Lists
 
-Given a template file `backends.tpl` with the following content:
+Given a template file `backends.tftpl` with the following content:
 
 ```
 %{ for addr in ip_addrs ~}
@@ -54,7 +59,7 @@ backend ${addr}:${port}
 The `templatefile` function renders the template:
 
 ```
-> templatefile("${path.module}/backends.tpl", { port = 8080, ip_addrs = ["10.0.0.1", "10.0.0.2"] })
+> templatefile("${path.module}/backends.tftpl", { port = 8080, ip_addrs = ["10.0.0.1", "10.0.0.2"] })
 backend 10.0.0.1:8080
 backend 10.0.0.2:8080
 
@@ -62,7 +67,7 @@ backend 10.0.0.2:8080
 
 ### Maps
 
-Given a template file `config.tmpl` with the following content:
+Given a template file `config.tftpl` with the following content:
 
 ```
 %{ for config_key, config_value in config }
@@ -74,7 +79,7 @@ The `templatefile` function renders the template:
 
 ```
 > templatefile(
-               "${path.module}/config.tmpl",
+               "${path.module}/config.tftpl",
                {
                  config = {
                    "x"   = "y"
@@ -113,7 +118,7 @@ ${yamlencode({
 })}
 ```
 
-Given the same input as the `backends.tmpl` example in the previous section,
+Given the same input as the `backends.tftpl` example in the previous section,
 this will produce a valid JSON or YAML representation of the given data
 structure, without the need to manually handle escaping or delimiters.
 In the latest examples above, the repetition based on elements of `ip_addrs` is

website/docs/language/settings/backends/configuration.html.md

@@ -70,16 +70,15 @@ automatically by an automation script running Terraform. When some or all of
 the arguments are omitted, we call this a _partial configuration_.
 
 With a partial configuration, the remaining configuration arguments must be
-provided as part of
+provided as part of [the initialization process](/docs/cli/init/index.html).
-[the initialization process](/docs/cli/init/index.html).
+
 There are several ways to supply the remaining arguments:
 
   * **File**: A configuration file may be specified via the `init` command line.
     To specify a file, use the `-backend-config=PATH` option when running
     `terraform init`. If the file contains secrets it may be kept in
-    a secure data store, such as
+    a secure data store, such as [Vault](https://www.vaultproject.io/),
-    [Vault](https://www.vaultproject.io/), in which case it must be downloaded
+    in which case it must be downloaded to the local disk before running Terraform.
-    to the local disk before running Terraform.
 
   * **Command-line key/value pairs**: Key/value pairs can be specified via the
     `init` command line. Note that many shells retain command-line flags in a
@@ -111,6 +110,8 @@ terraform {
 }
 ```
 
+### File
+
 A backend configuration file has the contents of the `backend` block as
 top-level attributes, without the need to wrap it in another `terraform`
 or `backend` block:
@@ -121,6 +122,13 @@ path    = "example_app/terraform_state"
 scheme  = "https"
 ```
 
+`*.backendname.tfbackend` (e.g. `config.consul.tfbackend`) is the recommended
+naming pattern. Terraform will not prevent you from using other names but following
+this convention will help your editor understand the content and likely provide
+better editing experience as a result.
+
+### Command-line key/value pairs
+
 The same settings can alternatively be specified on the command line as
 follows:
 

website/docs/language/settings/backends/remote.html.md

@@ -139,7 +139,7 @@ terraform {
 Backend configuration file:
 
 ```hcl
-# backend.hcl
+# config.remote.tfbackend
 workspaces { name = "workspace" }
 hostname     = "app.terraform.io"
 organization = "company"
@@ -148,7 +148,7 @@ organization = "company"
 Running `terraform init` with the backend file:
 
 ```sh
-terraform init -backend-config=backend.hcl
+terraform init -backend-config=config.remote.tfbackend
 ```
 
 ### Data Source Configuration