Fix style being missed on patchDocument

There were scenarios in which patching a document would result in loss
of style for the template runs and, possibly, their right-adjacent run
as well (post-splitting). That was due to the run style elements not
being added to the newly created runs.

This commit addresses this issue by introducing a new, optional, flag
for the `patchDocument` function: `keepOriginalStyles`. It defaults to
`false` (current behavior) and, when `true`, ensures that there is no
loss of styling.

This should address https://github.com/dolanmiu/docx/issues/2293.

src/patcher/from-docx.ts

@@ -49,6 +49,7 @@ export type IPatch = ParagraphPatch | FilePatch;
 
 export interface PatchDocumentOptions {
     readonly patches: { readonly [key: string]: IPatch };
+    readonly keepOriginalStyles?: boolean;
 }
 
 const imageReplacer = new ImageReplacer();
@@ -128,6 +129,7 @@ export const patchDocument = async (data: InputDataType, options: PatchDocumentO
                     patchText,
                     renderedParagraphs,
                     context,
+                    options.keepOriginalStyles,
                 );
             }