Merge pull request #344 from SuperSandro2000/fix-links-1.x

Fix redirected, outdated links and convert all to https

public/docs/features.md

@@ -35,7 +35,7 @@ The editor view, which is in night mode by default, can also be toggled between
 
 You can upload an image simply by clicking on the upload button <i class="fa fa-upload"></i>.
 Alternatively, you can **drag-n-drop** an image into the editor. Even **pasting** images is possible!
-This will automatically upload the image to **[imgur](http://imgur.com)**, **[Amazon S3](https://aws.amazon.com/s3/)**, **[Minio](https://minio.io)** or the **local filesystem** (depending on the instance's configuration), nothing to worry about. :tada:
+This will automatically upload the image to **[imgur](https://imgur.com)**, **[Amazon S3](https://aws.amazon.com/s3/)**, **[Minio](https://minio.io)** or the **local filesystem** (depending on the instance's configuration), nothing to worry about. :tada:
 
 ![imgur](https://i.imgur.com/9cgQVqD.png)
 
@@ -151,7 +151,7 @@ Use the syntax `[TOC]` to embed a table of contents into your note.
 
 You can type any emoji like this :smile: :smiley: :cry: :wink:
 
-> See full emoji list [here](http://www.emoji-cheat-sheet.com/).
+> See full emoji list [here](https://www.webfx.com/tools/emoji-cheat-sheet/).
 
 ### ToDo List
 
@@ -250,7 +250,7 @@ When you’re a carpenter making a beautiful chest of drawers, you’re not goin
 
 ### MathJax
 
-You can render *LaTeX* mathematical expressions using **MathJax**, as on [math.stackexchange.com](http://math.stackexchange.com/):
+You can render *LaTeX* mathematical expressions using **MathJax**, as on [math.stackexchange.com](https://math.stackexchange.com/):
 
 The *Gamma function* satisfying $\Gamma(n) = (n-1)!\quad\forall n\in\mathbb N$ is via the Euler integral
 
@@ -262,7 +262,7 @@ $$
 \Gamma(z) = \int_0^\infty t^{z-1}e^{-t}dt\,.
 $$
 
-> More information about **LaTeX** mathematical expressions [here](http://meta.math.stackexchange.com/questions/5020/mathjax-basic-tutorial-and-quick-reference).
+> More information about **LaTeX** mathematical expressions [here](https://meta.math.stackexchange.com/questions/5020/mathjax-basic-tutorial-and-quick-reference).
 
 ### Diagrams
 
@@ -278,7 +278,7 @@ Note left of Alice: Alice responds
 Alice->Bob: Where have you been?
 ```
 
-More information about **sequence diagrams** syntax [here](http://bramp.github.io/js-sequence-diagrams/).
+More information about **sequence diagrams** syntax [here](https://bramp.github.io/js-sequence-diagrams/).
 
 #### Flow Charts
 
@@ -296,7 +296,7 @@ cond(yes)->e
 cond(no)->op2
 ```
 
-More information about **flow charts** syntax [here](http://adrai.github.io/flowchart.js/).
+More information about **flow charts** syntax [here](https://flowchart.js.org/).
 
 #### Graphviz
 
@@ -314,7 +314,7 @@ digraph hierarchy {
 }
 ```
 
-More information about **graphviz** syntax [here](http://www.tonyballantyne.com/graphs.html)
+More information about **graphviz** syntax [here](https://www.tonyballantyne.com/graphs.html)
 
 #### Mermaid
 
@@ -331,7 +331,7 @@ gantt
   Another task: 24d
 ```
 
-More information about **mermaid** syntax [here](http://knsv.github.io/mermaid)
+More information about **mermaid** syntax [here](https://mermaid-js.github.io/mermaid/)
 
 #### Abc Music Notation
 
@@ -347,7 +347,7 @@ GABc dedB|dedB dedB|c2ec B2dB|A2F2 G4:|
 g2gf g2Bd|g2f2 e2d2|c2ec B2dB|A2F2 G4:|
 ```
 
-More information about **abc** syntax [here](http://abcnotation.com/learn)
+More information about **abc** syntax [here](https://abcnotation.com/learn)
 
 ### Alert Area