chore: fix typos and link broken (#118)

Signed-off-by: snoppy <michaleli@foxmail.com>

Author: xiaoxianBoy

docs/design/roadmap.md

@@ -6,6 +6,6 @@ tags: roadmap, nano, future, release, design
 
 # Roadmap
 
-- Node implemenation <a href="https://github.com/orgs/nanocurrency/projects/5" target="_blank">Roadmap</a>
+- Node implementation <a href="https://github.com/orgs/nanocurrency/projects/5" target="_blank">Roadmap</a>
 - Network <a href="https://docs.nano.org/releases/network-upgrades/" target="_blank">upgrade schedule</a>
 - Next planned <a href="https://docs.nano.org/releases/node-releases/#next-planned-release" target="_blank">node release</a>

docs/getting-started-devs/getting-started.md

@@ -118,7 +118,7 @@ account_id = nanolib.generate_account_id(seed, 0)
 
 | Name                                               | Description                                                                                                     |
 | -------------------------------------------------- | --------------------------------------------------------------------------------------------------------------- |
-| [nanodart](https://github.com/nano-dart/nano-dart) | Dart library for the NANO and BANANO cryptocurrencies - supports key generation, signing, encryption, and more. |
+| [nanodart](https://github.com/appditto/nanodart) | Dart library for the NANO and BANANO cryptocurrencies - supports key generation, signing, encryption, and more. |
 | [nanoutil](https://github.com/perishllc/nanoutil)  | A Nano and Banano cryptocurrency library for the Dart programming language                                      |
 
 ##### Python
@@ -277,4 +277,4 @@ Once you have a node up and running the ledger should bootstrap from the network
 - wallets (<a href="https://github.com/Nault/Nault" target="_blank">Nault</a> / <a href="https://github.com/appditto/natrium_wallet_flutter" target="_blank">Natrium</a>)
 - merchant payment services
 - streaming plugins for payments, tips, donations
-- pay per use intergation (articles)
+- pay per use integration (articles)

docs/introduction/investment-thesis.md

@@ -28,7 +28,7 @@ At this moment, the value comes mostly from speculation rather than actual payme
 
 Like with any new technology, it is not worth very much until it is worth a lot.
 
-In the meantime, critics will continually reference its lack of use by ordinary consumers and merchants, while overlooking its potential use. Over time, more and more consumers and merchants will adopt it as developers rapidly improve its useability to make it more accessible. The Internet was at first hard to use and now everyone is using it.
+In the meantime, critics will continually reference its lack of use by ordinary consumers and merchants, while overlooking its potential use. Over time, more and more consumers and merchants will adopt it as developers rapidly improve its usability to make it more accessible. The Internet was at first hard to use and now everyone is using it.
 
 ### Notable Quotes