Update INIConfigIO.md

Author: usa-m

docs/usage/INIConfigIO.md

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+# INIConfigIO
+
+DDS.Net.Connector.Helpers.**INIConfigIO** provides an easy to use interface for reading and writing INI files. Its constructor simply takes the INI file name and an optional implementation of [ILogger](./ILogger.md) interface:
+
+```csharp
+INIConfigIO(string filename, ILogger? logger = null)
+```
+
+It can be simply instantiated:
+
+```csharp
+INIConfigIO iniFile = new INIConfigIO("file.ini");
+```
+
+
+Its instance functions help in reading and writing the INI file, they include:
+
+  * Clear() - Clears the in-memory data but does not effect the file till it is saved.
+  * SaveFile() - Saves the in-memory data into the given file.
+  
+  * IEnumerable<string> GetSectionNames() - Gets all the section names present in the file.
+  * string GetString(string key, string defaultValue = "") - Gets a value as a string, default value is returned when the key is not present in the file.
+  * int GetInteger(string key, int defaultValue = -1) - Gets a value as an integer, default value is returned when the key is not present in the file.
+  * float GetFloat(string key, float defaultValue = 0) - Gets a value as a float, default value is returned when the key is not present in the file.
+  * double GetDouble(string key, double defaultValue = 0) - Gets a value as a double, default value is returned when the key is not present in the file.
+  
+  * SetString(string key, string value) - Sets specified key's value to the given value
+  * SetInteger(string key, int value) - Sets specified key's value to the given value
+  * SetFloat(string key, float value) - Sets specified key's value to the given value
+  * SetDouble(string key, double value) - Sets specified key's value to the given value
+
+
+For example, consider the following file:
+
+```ini
+[A]
+a = 5
+b = 6
+
+[B]
+a = 10
+b = 20
+```
+
+
+Its values can be read as:
+
+```csharp
+INIConfigIO iniFile = new INIConfigIO("file.ini");
+
+string value1 = iniFile.GetString("A/a"); // "5"
+string value2 = iniFile.GetString("A/b"); // "6"
+
+int value3 = iniFile.GetInteger("B/a"); // 10
+int value4 = iniFile.GetInteger("B/b"); // 20
+```
+
+
+