Add Quartiles method to Float64Data type (issue #60)

* chore: git ignore vscode config workspace
* feat: method to get  quartiles without input/argument from the initiated data64float
* test: fix test for method Quartiles

.gitignore

@@ -1,4 +1,5 @@
 coverage.out
 release-notes.txt
 .directory
-.chglog
+.chglog
+.vscode

data.go

@@ -162,3 +162,8 @@ func (f Float64Data) SoftMax() ([]float64, error) {
 func (f Float64Data) Entropy() (float64, error) {
 	return Entropy(f)
 }
+
+// Quartiles returns the three quartile points from instance of Float64Data
+func (f Float64Data) Quartiles() (Quartiles, error) {
+	return Quartile(f)
+}

data_test.go

@@ -269,3 +269,10 @@ func BenchmarkMethodsAPI(b *testing.B) {
 		_, _ = data.Mode()
 	}
 }
+
+func TestQuartilesMethods(t *testing.T) {
+	_, err := data1.Quartiles()
+	if err != nil {
+		t.Errorf("%s returned an error", getFunctionName(data1.Quartiles))
+	}
+}