Doc: update meshio min version

Author: MuellerSeb

README.md

@@ -350,7 +350,7 @@ in memory for immediate 3D plotting in Python.
 - [hankel >= 1.0.0](https://github.com/steven-murray/hankel)
 - [emcee >= 3.0.0](https://github.com/dfm/emcee)
 - [pyevtk >= 1.1.1](https://github.com/pyscience-projects/pyevtk)
-- [meshio >= 4.0.0](https://github.com/nschloe/meshio)
+- [meshio >= 5.1.0](https://github.com/nschloe/meshio)
 
 ### Optional
 

docs/source/index.rst

@@ -417,7 +417,7 @@ Requirements
 - `hankel >= 1.0.0 <https://github.com/steven-murray/hankel>`_
 - `emcee >= 3.0.0 <https://github.com/dfm/emcee>`_
 - `pyevtk >= 1.1.1 <https://github.com/pyscience-projects/pyevtk>`_
-- `meshio >= 4.0.0 <https://github.com/nschloe/meshio>`_
+- `meshio >= 5.1.0 <https://github.com/nschloe/meshio>`_
 
 
 Optional