add "icons-prefix" option and sets to "fa" (#14)

Author: HelloSebastian

README.md

@@ -587,6 +587,7 @@ Table Dataset are provided directly to the `bootstrap-table` as data-attributes
 | locale                     | string | "en-US"                                                     |
 | advanced-search            | bool   | true                                                        |
 | id-table                   | string | class name of table with counter. (`$this->getTableName()`) |
+| icons-prefix               | string | "fa"                                                        |
 | click-to-select            | bool   | true                                                        |
 | show-jump-to               | bool   | true                                                        |
 | show-export                | bool   | true                                                        |

src/HelloBootstrapTable.php

@@ -256,6 +256,7 @@ protected function configureTableDataset(OptionsResolver $resolver)
             "locale" => "en-US",
             "advanced-search" => true,
             "id-table" => $this->getTableName(),
+            "icons-prefix" => "fa",
 
             //extensions
             "click-to-select" => true,
@@ -294,6 +295,7 @@ protected function configureTableDataset(OptionsResolver $resolver)
         $resolver->setAllowedTypes("sort-reset", ["bool"]);
         $resolver->setAllowedTypes("pagination-V-Align", ["string"]);
         $resolver->setAllowedTypes("undefined-text", ["string"]);
+        $resolver->setAllowedTypes("icons-prefix", ["string"]);
         $resolver->setAllowedTypes("locale", ["string"]);
         $resolver->setAllowedTypes("advanced-search", ["bool"]);
         $resolver->setAllowedTypes("id-table", ["string"]);