remix-solidity readme updated

remix-solidity/README.md

-# `remix-solidity`
+## Remix-Solidity
+[![npm version](https://badge.fury.io/js/remix-solidity.svg)](https://www.npmjs.com/package/remix-solidity)
+[![npm](https://img.shields.io/npm/dt/remix-solidity.svg?label=Total%20Downloads)](https://www.npmjs.com/package/remix-solidity)
+[![npm](https://img.shields.io/npm/dw/remix-solidity.svg)](https://www.npmjs.com/package/remix-solidity)
+[![GitHub](https://img.shields.io/github/license/mashape/apistatus.svg)](https://github.com/ethereum/remix/tree/master/LICENSE)
+[![contributions welcome](https://img.shields.io/badge/contributions-welcome-brightgreen.svg?style=flat)](https://github.com/ethereum/remix/issues)
 
-Provides:
 
+`remix-solidity` is a tool to load and run solidity compiler. It works underneath Remix IDE plugin "Solidity Compiler" which is used to load different versions of compiler and compile the smart contracts. 
+
+### Installation
+
+`npm install remix-solidity`
+
+### How to use
+
+`remix-solidity` exports:
+```
     {
         Compiler: Compiler,
         CompilerInput: CompilerInput
     }
+```
+`CompilerInput` can be used to form the [compiler input](https://github.com/ethereum/remix/blob/remix-solidity-readme/remix-solidity/src/compiler/types.ts#L1) by passing the [options](https://github.com/ethereum/remix/blob/remix-solidity-readme/remix-solidity/src/compiler/types.ts#L144)
+
+`Compiler` is a class containing various methods to perform compiler related actions. Have a look to `Compiler` interface:
+
+```
+class Compiler {
+    handleImportCall: (fileurl: string, cb: Function) => void;
+    event: EventManager;
+    state: CompilerState;
+    constructor(handleImportCall: (fileurl: string, cb: Function) => void);
+    /**
+     * @dev Setter function for CompilerState's properties (used by IDE)
+     * @param key key
+     * @param value value of key in CompilerState
+     */
+    set<K extends keyof CompilerState>(key: K, value: CompilerState[K]): void;
+    /**
+     * @dev Internal function to compile the contract after gathering imports
+     * @param files source file
+     * @param missingInputs missing import file path list
+     */
+    internalCompile(files: Source, missingInputs?: string[]): void;
+    /**
+     * @dev Compile source files (used by IDE)
+     * @param files source files
+     * @param target target file name (This is passed as it is to IDE)
+     */
+    compile(files: Source, target: string): void;
+    /**
+     * @dev Called when compiler is loaded, set current compiler version
+     * @param version compiler version
+     */
+    onCompilerLoaded(version: string): void;
+    /**
+     * @dev Called when compiler is loaded internally (without worker)
+     */
+    onInternalCompilerLoaded(): void;
+    /**
+     * @dev Called when compilation is finished
+     * @param data compilation result data
+     * @param missingInputs missing imports
+     * @param source Source
+     */
+    onCompilationFinished(data: CompilationResult, missingInputs?: string[], source?: SourceWithTarget): void;
+    /**
+     * @dev Load compiler using given URL (used by IDE)
+     * @param usingWorker if true, load compiler using worker
+     * @param url URL to load compiler from
+     */
+    loadVersion(usingWorker: boolean, url: string): void;
+    /**
+     * @dev Load compiler using 'script' element (without worker)
+     * @param url URL to load compiler from
+     */
+    loadInternal(url: string): void;
+    /**
+     * @dev Load compiler using web worker
+     * @param url URL to load compiler from
+     */
+    loadWorker(url: string): void;
+    /**
+     * @dev Gather imports for compilation
+     * @param files file sources
+     * @param importHints import file list
+     * @param cb callback
+     */
+    gatherImports(files: Source, importHints?: string[], cb?: gatherImportsCallbackInterface): void;
+    /**
+     * @dev Truncate version string
+     * @param version version
+     */
+    truncateVersion(version: string): string;
+    /**
+     * @dev Update ABI according to current compiler version
+     * @param data Compilation result
+     */
+    updateInterface(data: CompilationResult): CompilationResult;
+    /**
+     * @dev Get contract obj of the given contract name from last compilation result.
+     * @param name contract name
+     */
+    getContract(name: string): Record<string, any> | null;
+    /**
+     * @dev Call the given callback for all the contracts from last compilation result
+     * @param cb callback
+     */
+    visitContracts(cb: visitContractsCallbackInterface): void | null;
+    /**
+     * @dev Get the compiled contracts data from last compilation result
+     */
+    getContracts(): CompilationResult['contracts'] | null;
+    /**
+     * @dev Get sources from last compilation result
+     */
+    getSources(): Source | null | undefined;
+    /**
+     * @dev Get sources of passed file name from last compilation result
+     * @param fileName file name
+     */
+    getSource(fileName: string): Source['filename'] | null;
+    /**
+     * @dev Get source name at passed index from last compilation result
+     * @param index    - index of the source
+     */
+    getSourceName(index: number): string | null;
+}
+```
+
+## Contribute
+
+Please feel free to open an issue or a pull request. 
+
+In case you want to add a code, do have a look to our contribution guidelnes [here](https://github.com/ethereum/remix/blob/master/CONTRIBUTING.md). Reach us in [Gitter](https://gitter.im/ethereum/remix) in case of any queries.
+
+## License
+
+[MIT](../LICENSE) © 2020 Remix Team