Added main plugin file

caldera-fix.php

@@ -0,0 +1,33 @@
+<?php
+/**
+ * Plugin Name: Caldera Fix
+ * Plugin URI: http://orangedoghost.com
+ * Description: Fix for Caldera forms mime type.
+ * Version: 0.3.1
+ * Author: Zack Palmer (zacnoo)
+ */
+
+/**
+ * Support for 'text/plain' as the secondary(?) mime type of .json files
+ */
+add_filter( 'wp_check_filetype_and_ext', 'wpse323750_secondary_mime', 99, 4 );    
+function wpse323750_secondary_mime( $check, $file, $filename, $mimes ) {
+    if ( empty( $check['ext'] ) && empty( $check['type'] ) ) {
+        $secondary_mime = [ 'json' => 'application/json' ];
+        // Run another check, but only for our secondary mime and not on core mime types.
+        remove_filter( 'wp_check_filetype_and_ext', 'wpse323750_secondary_mime', 99, 4 );
+        $check = wp_check_filetype_and_ext( $file, $filename, $secondary_mime );
+        add_filter( 'wp_check_filetype_and_ext', 'wpse323750_secondary_mime', 99, 4 );
+    }
+    return $check;
+}
+
+
+function my_theme_custom_upload_mimes( $existing_mimes ) {
+	// Add json to the list of mime types.
+	$existing_mimes['json'] = 'application/json';
+
+	// Return the array back to the function with our added mime type.
+	return $existing_mimes;
+}
+add_filter( 'mime_types', 'my_theme_custom_upload_mimes' );