Dev 1.x some doc mistakes

[KevinNuNu]

Modification

Some doc mistakes in user_guiders markdown file:
1.dataset_prepare.md , config path to icdar2015.py was wrong
2.dataset_prepare.md , icdar2015's config content was wrong
3.visualization.md, default_runtime.py Visualization's param is visualizer not Visualizer

[CLAassistant]

All committers have signed the CLA.

[gaotongxiao]

Hi, thanks for your contribution! Before we are able to merge your PR, please don't forget to sign CLA here :)

Also, if you get an error message like "xxx seems not to be a GitHub user", it means that the email you used to commit changes does not match the one you used in your GitHub account. You can try to link your local email to your GitHub, or update your local email address and then amend your commits:

git config --global user.email "YOUR_GITHUB_EMAIL"
git commit --amend

[KevinNuNu]

Hi, thanks for your contribution! Before we are able to merge your PR, please don't forget to sign CLA here :)

Also, if you get an error message like "xxx seems not to be a GitHub user", it means that the email you used to commit changes does not match the one you used in your GitHub account. You can try to link your local email to your GitHub, or update your local email address and then amend your commits:

git config --global user.email "YOUR_GITHUB_EMAIL"
git commit --amend

I'm done.