feat: render math equations in .docx documents (#1160)

* feat: math equation rendering in .docx files
* fix: import fix on .docx pre processing
* test: add test cases for docx equation rendering
* docs: add ThirdPartyNotices.md
* refactor: reformatted with black

packages/markitdown/pyproject.toml

@@ -38,6 +38,7 @@ all = [
   "pandas",
   "openpyxl",
   "xlrd",
+  "lxml",
   "pdfminer.six",
   "olefile",
   "pydub",
@@ -47,7 +48,7 @@ all = [
   "azure-identity"
 ]
 pptx = ["python-pptx"]
-docx = ["mammoth"]
+docx = ["mammoth", "lxml"]
 xlsx = ["pandas", "openpyxl"]
 xls = ["pandas", "xlrd"]
 pdf = ["pdfminer.six"]