git: Add Guix manifest and run script.

guix.sh

@@ -0,0 +1,3 @@
+#!/usr/bin/env bash
+
+guix shell --manifest=manifest.scm -- python3 ./src/pamhyr.py $@

manifest.scm

@@ -0,0 +1,22 @@
+;; manifest.scm -- Pamhyr2 Guix manifest
+;; Copyright (C) 2025  INRAE
+;;
+;; This program is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+;;
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+;;
+;; You should have received a copy of the GNU General Public License
+;; along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+(specifications->manifest
+ (list "python" "python-platformdirs" "python-lxml"
+       "python-pyqt@5" "python-pyqt5-sip"
+       "python-pyqtgraph" "python-qscintilla"
+       "python-numpy@1" "python-shapely" "python-pyshp"
+       "python-matplotlib" "python-rasterio"))