Update quickstart pages

At a glance:

• memory requirements aren't correctly set
• Syncing blockchain needs to be redone, still a lot of steem references, we need one section using hive docker (copy paste some posts from @someguy123 and one section using plain hived see https://peakd.com/hive-160391/@gtg/witness-update-release-candidate-for-eclipse-is-out. Overall that section should add links to the other pages so that the user understands what plugins are, what's a blog log etc. So that it's a "quickstart" but he can learn more if wanted
• Hive Testnet needs to be done, we don't have an official testnet so might as well just create the "runnig a custom testnet" here and add a new section if we have a permanent testnet in the future. you can use @howo's tutorial here as an example (the hf24 part obviously and without HIVE_HF24_TIME since we already forked): https://peakd.com/hive/@howo/how-to-participate-in-the-tesntets-this-week-full-guide
• remove tinman from here, quickstart shouldn't involve tinman as it's more advanced. At best we should have a link to it's page
• Running a Testnet Node should be removed in favor of "hive testnets"
• Custom Testnet needs to be redone or just straight up removed.