Add docstring

Author: Vaibhavdixit02

src/lbfgsb.jl

@@ -1,5 +1,17 @@
 using Optimization.SciMLBase, LBFGSB
 
+"""
+$(TYPEDEF)
+
+L-BFGS-B Nonlinear Optimization Code from [LBFGSB](https://github.com/Gnimuc/LBFGSB.jl/tree/master).
+It is a quasi-Newton optimization algorithm that supports bounds.
+
+References
+
+- R. H. Byrd, P. Lu and J. Nocedal. A Limited Memory Algorithm for Bound Constrained Optimization, (1995), SIAM Journal on Scientific and Statistical Computing , 16, 5, pp. 1190-1208.
+- C. Zhu, R. H. Byrd and J. Nocedal. L-BFGS-B: Algorithm 778: L-BFGS-B, FORTRAN routines for large scale bound constrained optimization (1997), ACM Transactions on Mathematical Software, Vol 23, Num. 4, pp. 550 - 560.
+- J.L. Morales and J. Nocedal. L-BFGS-B: Remark on Algorithm 778: L-BFGS-B, FORTRAN routines for large scale bound constrained optimization (2011), to appear in ACM Transactions on Mathematical Software.
+"""
 @kwdef struct LBFGS
     m::Int=10
 end