Added nGQL.md (#30)

CONTRIBUTING.md

+## Workflow
+
+### Step 1: Fork in the cloud
+
+1. Visit https://github.com/vesoft-inc/vgraph
+2. Click `Fork` button (top right) to establish a cloud-based fork.
+
+### Step 2: Clone fork to local storage
+
+Define a local working directory:
+
+```sh
+# Define your working directory
+working_dir=$HOME/Workspace
+```
+
+Set `user` to match your github profile name:
+
+```sh
+user={your github profile name}
+```
+
+Create your clone:
+
+```sh
+mkdir -p $working_dir
+cd $working_dir
+git clone https://github.com/$user/vgraph.git
+# the following is recommended
+# or: git clone git@github.com:$user/vgraph.git
+
+cd $working_dir/vgraph
+git remote add upstream https://github.com/vesoft-inc/vgraph.git
+# or: git remote add upstream git@github.com:vesoft-inc/vgraph.git
+
+# Never push to upstream master since you do not have write access.
+git remote set-url --push upstream no_push
+
+# Confirm that your remotes make sense:
+# It should look like:
+# origin    git@github.com:$(user)/vgraph.git (fetch)
+# origin    git@github.com:$(user)/vgraph.git (push)
+# upstream  https://github.com/vesoft-inc/vgraph (fetch)
+# upstream  no_push (push)
+git remote -v
+```
+
+#### Define a pre-commit hook
+
+Please link the vGraph pre-commit hook into your `.git` directory.
+
+This hook checks your commits for formatting, building, doc generation, etc.
+
+```sh
+cd $working_dir/vgraph/.git/hooks
+ln -s ../../hooks/pre-commit .
+```
+Sometime, pre-commit hook can not be executable. In such case, you have to make it executable manually.
+
+```sh
+cd $working_dir/vgraph/.git/hooks
+chmod +x pre-commit
+```
+
+### Step 3: Branch
+
+Get your local master up to date:
+
+```sh
+cd $working_dir/vgraph
+git fetch upstream
+git checkout master
+git rebase upstream/master
+```
+
+Branch from master:
+
+```sh
+git checkout -b myfeature
+```
+**NOTE**: Because your PR often consists of several commits, which might be squashed while being merged into upstream,
+we strongly suggest you open a separate topic branch to make your changes on. After merged,
+this topic branch could be just abandoned, thus you could synchronize your master branch with
+upstream easily with a rebase like above. Otherwise, if you commit your changes directly into master,
+maybe you must use a hard reset on the master branch, like:
+
+```sh
+git fetch upstream
+git checkout master
+git reset --hard upstream/master
+git push --force origin master
+```
+
+### Step 4: Develop
+
+#### Edit the code
+
+You can now edit the code on the `myfeature` branch. Please follow the coding style guidance [here](docs/cpp-coding-style.md)
+
+#### Run stand-alone mode
+
+If you want to reproduce and investigate an issue, you may need
+to run vGraph in stand-alone mode.
+
+```sh
+# Build the binary.
+make server
+
+# Run in stand-alone mode.
+vgraphd
+```
+
+Then you can connect the vGraph console to your local server
+```sh
+vgraph
+```
+
+#### Run Test
+
+```sh
+# Run unit test to make sure all test passed.
+```
+
+### Step 5: Keep your branch in sync
+
+```sh
+# While on your myfeature branch.
+git fetch upstream
+git rebase upstream/master
+```
+
+### Step 6: Commit
+
+Commit your changes.
+
+```sh
+git commit
+```
+
+Likely you'll go back and edit/build/test some more than `commit --amend`
+in a few cycles.
+
+### Step 7: Push
+
+When ready to review (or just to establish an offsite backup or your work),
+push your branch to your fork on `github.com`:
+
+```sh
+git push -f origin myfeature
+```
+
+### Step 8: Create a pull request
+
+1. Visit your fork at https://github.com/$user/vgraph (replace `$user` obviously).
+2. Click the `Compare & pull request` button next to your `myfeature` branch.
+
+### Step 9: Get a code review
+
+Once your pull request has been opened, it will be assigned to at least one
+reviewers. Those reviewers will do a thorough code review, looking for
+correctness, bugs, opportunities for improvement, documentation and comments,
+and style.
+
+Commit changes made in response to review comments to the same branch on your
+fork.
+
+Very small PRs are easy to review. Very large PRs are very difficult to
+review.

README.md

-## VEGraph
+## Nebula Graph
 
-A scalable, distributed graph database
+A high performance distributed graph database