Add involvement and repharse info

CONTRIBUTING.md

@@ -10,6 +10,16 @@ If you would like to learn more about how to get started contributing, see the
 interested in participating in Google Summer of Code, see
 [mlpack and Google Summer of Code](http://www.mlpack.org/gsoc.html).
 
+## Involving 
+
+It is not necessary to always code and contribute to mlpack codebase, There are several other ways to contribute to, Some of them could be :
+
+- Triaging a Bug Report: There are many issues raised daily and if you could confirm or create a reproducible code snippet to triage and confirm that issue, that would do a whole good of help
+
+- Involvement in Messaging Channel: Our messaging channel is very active, There are times when there are queries related to machine learning models or similar such issues, Which could be solved without writing code if you are versed with the topic and hence we would love to have people with good conceptual skills on board 
+
+- Documentation - Pull requests are not judged based on length, Improving the Documentation are often left unnoticed, and hence if you can improve docs in any way, we would be greatly thankful to you
+
 ## Pull request process
 
 Once a pull request is submitted, it must be approved by at least one member of
@@ -33,9 +43,9 @@ appreciated and encouraged!
 
 All mlpack contributors who choose to review and provide feedback on Pull Requests have a responsibility to both the project and the individual making the contribution. 
 
-Reviews and feedback must be helpful, insightful, and geared towards improving the contribution. If there are reasons why you feel the PR should not be merged, explain what those are. Do not expect to be able to block a Pull Request from advancing simply because you say "No" without giving an explanation. Be open to having your mind changed. Be open to working with the contributor to make the Pull Request better.
+Reviews and feedback must be [helpful, insightful, and geared towards improving the contribution](https://www.youtube.com/watch?v=NNXk_WJzyMI). If there are reasons why you feel the PR should not be merged, explain what those are. Do not expect to be able to block a Pull Request from advancing simply because you say "No" without giving an explanation. Be open to having your mind changed. Be open to working with the contributor to make the Pull Request better.
 
-Reviews that are dismissive or disrespectful of the contributor or any other reviewers are strictly prohibited.
+Please don't leave dismissive or disrespectful reviews!  It's not helpful for anyone.
 
 When reviewing a Pull Request, the primary goals are :
 
@@ -52,8 +62,6 @@ Let's welcome new contributors with <3, and not overwhelm them.
 
 ## Pull Request Waiting Time 
 
-Since all those associated with the project are working during their free time to improve the project, It sometimes becomes difficult to spare time for a particular pull request and hence please wait patiently until one of the contributors or maintainers reviews your pull request or patches. 
-
-There is a minimum waiting time which we try to respect, so that people who may have important input in such a huge project are able to respond 
+Since members of the Contributors team only work on mlpack in their free time, it may take some time for them to review pull requests. While gentle reminders are welcome, please be patient and avoid constantly messaging the contributors.
 
-Constant pinging or getting in touch to get the pull request wouldn't be of much help and may overload the maintainer which could potentialy reduce the throughput.
+Typically small PRs will be reviewed within a handful of days; larger PRs might take a few weeks for an initial review, and it may be a little bit longer in times of high activity.