isotopes: add Gonfiantini 1986 example with fig. 3-1 reproduction (Rayleigh distillation for different RH for 2H and 18O + GMWL) (#1521)

Co-authored-by: Sylwester Arabas <[email protected]>

Author: AgnieszkaZaba

docs/bibliography.json

@@ -763,5 +763,12 @@
     ],
     "title": "A physical model of Titan’s clouds",
     "label": "Toon et al. 1980 (Icarus 43)"
+  },
+  "https://doi.org/10.1016/B978-0-444-42225-5.50008-5": {
+    "usages": [
+      "examples/PySDM_examples/Gonfiantini_1986/fig_3_1.ipynb"
+    ],
+    "title": "Environmental isotopes in lake stadies",
+    "label": "Gonfiantini 1986 (The Terrestrial Environment, B)"
   }
 }