Remove duplicate "class" and convert "Class" to lowercase in "iostreams Conventions" topic

Author: Rageking8

docs/standard-library/iostreams-conventions.md

@@ -20,9 +20,9 @@ The iostreams headers support conversions between text and encoded forms, and in
 [`<streambuf>`](streambuf.md)\
 [`<strstream>`](strstream.md)
 
-The simplest use of iostreams requires only that you include the header [`<iostream>`](iostream.md). You can then extract values from [`cin`](iostream.md#cin) or [`wcin`](iostream.md#wcin) to read the standard input. The rules for doing so are outlined in the description of the class [`basic_istream` Class](basic-istream-class.md). You can also insert values to [`cout`](iostream.md#cout) or [`wcout`](iostream.md#wcout) to write the standard output. The rules for doing so are outlined in the description of the class [`basic_ostream` Class](basic-ostream-class.md). Format control common to both extractors and insertors is managed by the class [`basic_ios` Class](basic-ios-class.md). Manipulating this format information in the guise of extracting and inserting objects is the province of several manipulators.
+The simplest use of iostreams requires only that you include the header [`<iostream>`](iostream.md). You can then extract values from [`cin`](iostream.md#cin) or [`wcin`](iostream.md#wcin) to read the standard input. The rules for doing so are outlined in the description of the [`basic_istream` class](basic-istream-class.md). You can also insert values to [`cout`](iostream.md#cout) or [`wcout`](iostream.md#wcout) to write the standard output. The rules for doing so are outlined in the description of the [`basic_ostream` class](basic-ostream-class.md). Format control common to both extractors and insertors is managed by the [`basic_ios` class](basic-ios-class.md). Manipulating this format information in the guise of extracting and inserting objects is the province of several manipulators.
 
-You can perform the same iostreams operations on files that you open by name, using the classes declared in [`<fstream>`](fstream.md). To convert between iostreams and objects of class [`basic_string` Class](basic-string-class.md), use the classes declared in [`<sstream>`](sstream.md). To do the same with C strings, use the classes declared in [`<strstream>`](strstream.md).
+You can perform the same iostreams operations on files that you open by name, using the classes declared in [`<fstream>`](fstream.md). To convert between iostreams and objects of [`basic_string` class](basic-string-class.md), use the classes declared in [`<sstream>`](sstream.md). To do the same with C strings, use the classes declared in [`<strstream>`](strstream.md).
 
 The remaining headers provide support services, typically of direct interest to only the most advanced users of the iostreams classes.