Update README.md

Changes:
- fix typos and grammar
- improve formatting

Author: FastAlien

README.md

@@ -1,78 +1,93 @@
 # cpp-merge
-Tool to produce single source file from multiple C/C++ files. Is was developed mainly to use in programming contests
-in which solution must be submitted as single source file.
+
+Tool to produce a single source file from multiple C/C++ files. It was developed mainly to be used in programming
+contests that require submitting a solution as a single source file.
 
 ## Install
+
 #### Prerequisites
+
 * node
 * npm
 * yarn (optional)
 
 #### Installation from npm
+
 ```
 npm install -g cpp-merge
 ```
 
 #### Installation from source
+
 ##### Clone git repository
+
 ```
 git clone git@github.com:RandomVoid/cpp-merge.git
 ```
 
 ##### Build and link package
+
 Using npm:
+
 ```
 npm install
 npm run build
 npm link
 ```
 
 Or using yarn:
+
 ```
 yarn
 yarn build
 yarn link
 ```
 
 ## Usage
-This tool will produce single source file from multiple C/C++ files. By default produced content is displayed on
-the standard output. To save it into a file use option `-o` or `--output`.
 
-File passed as an argument will be processed similarly to what preprocessor would do. It means all included local
-files (ex. `#include "header.hpp"`) will processed and added to output in place of the include directive.
-Program will search for include files first in directory where currently processed file is located and then in
+This tool will produce a single source file from multiple C/C++ files. By default produced content is displayed on the
+standard output. To save it into a file use option `-o` or `--output`.
+
+File passed as an argument will be processed similarly to what the preprocessor would do. It means all included local
+files (ex. `#include "header.hpp"`) will be processed and added to output in place of the include directive. Program
+will search for include files first in the directory where the currently processed file is located and then in
 additional include directory, if it was specified in program arguments (option `-i` or `--include`).
 
 Files containing `#pragma once` will be processed only once, so use this directive to avoid duplication of content of
 files in the output and to reduce its size.
 
-After processing all included files, program will try to find related source file for each of included local header
-files. If file with same base name and extension .c or .cpp exists, it will be appended to the output. Program will
-search first in the same directory where main source file is located and then in additional source directory, if it was
-specified in program arguments (option `-s` or `--source`). If the header was included using relative path ex.
-`#include "one/two/three.hpp"` the program will search for `three.c` or `three.cpp` in `one/two/` or
-`${sourceDirectory}/one/two/`. First found file will be appended to the output.
+After processing all included files, the program will try to find related source files for each of included local header
+files. If a file with the same base name and extension .c or .cpp exists, it will be appended to the output. Program
+will search first in the same directory where the main source file is located and then in an additional source
+directory, if it was specified in program arguments (option `-s` or `--source`). If the header was included using
+relative path ex. `#include "one/two/three.hpp"` the program will search for `three.c` or `three.cpp` in `one/two/`
+or `${sourceDirectory}/one/two/`. First found file will be appended to the output.
 
-Program will detect duplication of system header includes, so output will contain only unique set of them, ordered
-alphabetically. Any of processed header and source files will not be changed.
+Program will detect duplication of system header includes, so output will contain only a unique set of them, ordered
+alphabetically. Any of the processed header and source files will not be changed.
+
+Display the build-in help:
 
-Display build-in help:
 ```
 cpp-merge --help
 ```
 
 #### Usage examples
-Process `main.cpp` and display produced content on standard output:
+
+Process `main.cpp` and display produced content on the standard output:
+
 ```
 cpp-merge main.cpp
 ```
 
 Process `main.cpp` and save output to file `output.cpp`:
+
 ```
 cpp-merge --output output.cpp main.cpp
 ```
 
 Specify additional include and source directory:
+
 ```
 cpp-merge --include ../include --source ../src main.cpp
-``` 
+```