Add references to phpcr-odm browsers on the docs.

[brunoreis]

It all begins with:

BrunoReis: Hi all. Good morning. (at least it’s morning here). Please, does anyone knows a good tool to explore a phpcr-odm repository?
[09:01am] BrunoReis: For now, the best solution I have is doctrine:phpcr:node:dump
...
And then dantleec1 asked me to create this issue.

It would be nice to have references to:

• https://github.com/marmelab/phpcr-browser
• https://github.com/phpcr/phpcr-shell

...in the docs. We've thought about these places:

• http://symfony.com/doc/master/cmf/book/database_layer.html
• http://symfony.com/doc/master/cmf/bundles/phpcr_odm/introduction.html

[dbu]

indeed, we should somehow explain this. for links, i think we best point to http://phpcr.github.io/tools/ as this is the place where we already have descriptions and where we would add more tools as they turn up.

in http://symfony.com/doc/master/cmf/bundles/phpcr_odm/introduction.html i would add a ..tip right at the end of the Installation section, saying that there are tools like the mysql cli and phpmyadmin for low level access to phpcr and point to the tools website.

in the database_layer, i would add something to the summary at the end.
additionally, http://symfony.com/doc/master/cmf/cookbook/database/choosing_phpcr_implementation.html could mention the tools and say that they work with all of those implementations.

do you want to do a pull request for this?

[brunoreis]

Not now. I might do it later when I have a little more time. (in one or two weeks I think)