toc_md: removed subtitle Implemented as proposed by Milan

Author: jvdp1

src/stdlib_experimental_io.md

@@ -1,7 +1,5 @@
 # IO
 
-## Implemented
-
 * [`loadtxt` - load a 2D array from a text file](#loadtxt---load-a-2d-array-from-a-text-file)
 * [`open` - open a file](#open---open-a-file)
 * [`savetxt` - save a 2D array into a text file](#savetxt---save-a-2d-array-into-a-text-file)

src/stdlib_experimental_optval.md

@@ -1,7 +1,5 @@
 # Default values for optional arguments
 
-## Implemented
-
 * [`optval` - fallback value for optional arguments](#optval---fallback-value-for-optional-arguments)
 
 ## `optval` - fallback value for optional arguments

src/stdlib_experimental_quadrature.md

@@ -1,7 +1,5 @@
 # Numerical integration
 
-## Implemented
-
 * [`trapz` - integrate sampled values using trapezoidal rule](#trapz---integrate-sampled-values-using-trapezoidal-rule)
 * [`trapz_weights` - trapezoidal rule weights for given abscissas](#trapz_weights---trapezoidal-rule-weights-for-given-abscissas)
 * [`simps` - integrate sampled values using Simpson's rule (to be implemented)](#simps---integrate-sampled-values-using-simpsons-rule-to-be-implemented)

src/stdlib_experimental_stats.md

@@ -1,8 +1,5 @@
 # Descriptive statistics
 
-
-## Implemented
-
 * [`mean` - mean of array elements](#mean---mean-of-array-elements)
 * [`moment` - central moment of array elements](#moment---central-moment-of-array-elements)
 * [`var` - variance of array elements](#var---variance-of-array-elements)