Add File Functions section to README template

Author: CodeShellDev

.github/templates/README.template.md

@@ -10,6 +10,7 @@
 
 - [Getting Started](#getting-started)
 - [Usage](#usage)
+  - [File Functions](#file-functions)
   - [String Functions](#string-functions)
   - [Container Functions](#container-functions)
   - [Parser Functions](#parser-functions)
@@ -44,11 +45,11 @@ Goplater uses Go's [builtin templating library](https://pkg.go.dev/text/template
 File Content: $​{​{​{ read "./myfile.txt" }​}​}
 ```
 
+### File Functions
+
 As you saw in the example above `read` is used for reading and output file contents.
 But there are more as you will see in the following…
 
-### String Functions
-
 #### `read`
 
 Reads from absolute or relative file path (depending on input),
@@ -78,6 +79,8 @@ Performs a get http request to the specified url.
 fetch "url"
 ```
 
+### String Functions
+
 #### `trim`
 
 Outputs trimmed string.