Дополнения в описание проекта / Some addions in the description of the project

docs/english/Prefixes.md

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+# Prefixes
+
+The library uses prefixes in names of types, constants and functions.
+
+The main prefix is **BG** which means **B**asic **G**eometry.
+
+The structure types have prefix in the form **Bg**. For example: *BgFP64Vector3*,
+*BgFP32Versor*, *BgFP32Matrix2x2*.
+
+The constants have prefix in the form **BG_**. For example: *BG_FP32_EPSYLON*,
+*BG_FP64_TWO_PI*.
+
+The functions have prefix in the form **bg_**. For example:
+*bg_fp32_versor_combine*, *bg_fp64_matrix3x3_subtract*.
+
+A prefix of type follows right after the prefix of the library. The library uses
+two types of floating point numbers: **float** and **double** (**binary32**
+and **binary64** types of the **IEEE 754** standard).
+
+Thus there are two prefixes of types:
+
+* **FP32** - means **F**loating **P**oint 32 bit, which corresponds to the
+**float** type of the C language.
+
+* **FP32** - means **F**loating **P**oint 64 bit, which corresponds to the
+**double** type of the C language.
+
+The types of structures which are based in the **float** type have **FP32** as
+the type prefix: BgFP32Vector3, BgFP32Matrix3x2, BgFP32Quaternion
+
+The types of structures which are based in the **double** type have **FP64** as
+the type prefix: BgFP64Vector2, BgFP64Matrix2x3, BgFP64Versor
+
+The constants of the **float** type have **FP32_** as the type prefix:
+BG_FP32_PI, BG_FP32_EPSYLON.
+
+The constants of the **double** type have **FP64_** as the type prefix:
+BG_FP64_HALF_PI, BG_FP64_ONE_THIRD.
+
+The functions which works with data of the **float** type have **fp32_** as
+the type prefix: bg_fp32_vector2_get_module, bg_fp32_radians_to_degrees.
+
+The functions which works with data of the **double** type have **fp64_** as
+the type prefix: bg_fp64_vector3_reset, bg_fp64_radians_normalize.

docs/english/Vector2.md

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+# Two dimensional vectors
+
+There are two types for two dimensional vectors:
+- BgFP32Vector2 for single precision vectors
+- BgFP64Vector2 for double precision vectors
+
+Vectors of BgFP32Vecto2 type use **float** (binary32 of IEEE 754) type to store
+coordinate values.
+
+Vectors of BgFP64Vecto2 type use **double** (binary64 of IEEE 754) type to store
+coordinate values.
+
+The both types are structures with two fields: **x1** and **x2**
+
+The definition of the types:
+
+    typedef struct
+    {
+        float x1, x2;
+    } BgFP32Vector2;
+
+    typedef struct
+    {
+        double x1, x2;
+    } BgFP64Vector2;
+