Add documentation for the IGC format.

src/ol/format/igcformat.exports

@@ -1,3 +1,4 @@
 @exportSymbol ol.format.IGC
 @exportProperty ol.format.IGC.prototype.readFeature
 @exportProperty ol.format.IGC.prototype.readFeatures
+@exportProperty ol.format.IGC.prototype.readProjection

src/ol/format/igcformat.js

@@ -85,6 +85,16 @@ ol.format.IGC.prototype.getExtensions = function() {
 };
 
 
+/**
+ * Read the feature from the IGC source.
+ *
+ * @function
+ * @param {ArrayBuffer|Document|Node|Object|string} source Source.
+ * @return {ol.Feature} Feature.
+ */
+ol.format.IGC.prototype.readFeature;
+
+
 /**
  * @inheritDoc
  */
@@ -156,6 +166,17 @@ ol.format.IGC.prototype.readFeatureFromText = function(text) {
 };
 
 
+/**
+ * Read the feature from the source. As IGC sources contain a single
+ * feature, this will return the feature in an array.
+ *
+ * @function
+ * @param {ArrayBuffer|Document|Node|Object|string} source Source.
+ * @return {Array.<ol.Feature>} Features.
+ */
+ol.format.IGC.prototype.readFeatures;
+
+
 /**
  * @inheritDoc
  */
@@ -169,6 +190,16 @@ ol.format.IGC.prototype.readFeaturesFromText = function(text) {
 };
 
 
+/**
+ * Read the projection from the IGC source.
+ *
+ * @function
+ * @param {ArrayBuffer|Document|Node|Object|string} source Source.
+ * @return {ol.proj.Projection} Projection.
+ */
+ol.format.IGC.prototype.readProjection;
+
+
 /**
  * @inheritDoc
  */