chore: add references for order types (leanprover-community#34739)

Author: Ruben-VandeVelde

Mathlib/Order/Types/Arithmetic.lean

@@ -30,9 +30,10 @@ The following are notations in the `OrderType` namespace:
 ## References
 
 * <https://en.wikipedia.org/wiki/Order_type>
-* Dauben, J. W. Georg Cantor: His Mathematics and Philosophy of the Infinite. Princeton,
-  NJ: Princeton University Press, 1990.
-* Enderton, Herbert B. Elements of Set Theory. United Kingdom: Academic Press, 1977.
+* [Dauben, J. W., Georg Cantor: His Mathematics and Philosophy of the Infinite. Princeton,
+  NJ: Princeton University Press, 1990.][dauben_1990]
+* [Enderton, Herbert B., Elements of Set Theory. United Kingdom: Academic Press,
+  1977.][enderton_1977]
 
 ## Tags
 

Mathlib/Order/Types/Defs.lean

@@ -30,9 +30,10 @@ The following are notations in the `OrderType` namespace:
 ## References
 
 * <https://en.wikipedia.org/wiki/Order_type>
-* Dauben, J. W. Georg Cantor: His Mathematics and Philosophy of the Infinite. Princeton,
-  NJ: Princeton University Press, 1990.
-* Enderton, Herbert B. Elements of Set Theory. United Kingdom: Academic Press, 1977.
+* [Dauben, J. W., Georg Cantor: His Mathematics and Philosophy of the Infinite. Princeton,
+  NJ: Princeton University Press, 1990.][dauben_1990]
+* [Enderton, Herbert B., Elements of Set Theory. United Kingdom: Academic Press,
+  1977.][enderton_1977]
 
 ## Tags
 

docs/references.bib

@@ -1443,6 +1443,15 @@ @Article{         crans2017
   url           = {https://doi.org/10.1007/s40062-016-0164-9}
 }
 
+@Book{            dauben_1990,
+  place         = {Princeton, NJ},
+  title         = {Georg Cantor: His Mathematics and Philosophy of the
+                  Infinite},
+  publisher     = {Princeton University Press},
+  author        = {Dauben, Joseph W.},
+  year          = {1990}
+}
+
 @Book{            davey_priestley,
   author        = {Davey, B. A. and Priestley, H. A.},
   title         = {Introduction to lattices and order},
@@ -1746,6 +1755,14 @@ @Article{         elliott2006binomial
   doi           = {10.1016/j.jpaa.2005.09.003}
 }
 
+@Book{            enderton_1977,
+  place         = {New York},
+  title         = {Elements of set theory},
+  publisher     = {Academic Press},
+  author        = {Enderton, Herbert B.},
+  year          = {1977}
+}
+
 @Book{            engel1997,
   title         = {Sperner theory},
   author        = {Engel, Konrad},