Merge branch 'develop' into docs/2910_update-contributing-guidelines

packages/mermaid/src/docs/syntax/flowchart.md

@@ -10,6 +10,14 @@ Flowcharts are composed of **nodes** (geometric shapes) and **edges** (arrows or
 If you are using the word "end" in a Flowchart node, capitalize the entire word or any of the letters (e.g., "End" or "END"), or apply this [workaround](https://github.com/mermaid-js/mermaid/issues/1444#issuecomment-639528897). Typing "end" in all lowercase letters will break the Flowchart.
 ```
 
+```warning
+If you are using the letter "o" or "x" as the first letter in a connecting Flowchart node, add a space before the letter or capitalize the letter (e.g., "dev--- ops", "dev---Ops").
+
+Typing "A---oB" will create a [circle edge](#circle-edge-example).
+
+Typing "A---xB" will create a [cross edge](#cross-edge-example).
+```
+
 ### A node (default)
 
 ```mermaid-example
@@ -305,17 +313,28 @@ flowchart TB
     B --> D
 ```
 
-### New arrow types
+## New arrow types
 
-There are new types of arrows supported as per below:
+There are new types of arrows supported:
+
+- circle edge
+- cross edge
+
+### Circle edge example
 
 ```mermaid-example
 flowchart LR
     A --o B
-    B --x C
 ```
 
-### Multi directional arrows
+### Cross edge example
+
+```mermaid-example
+flowchart LR
+    A --x B
+```
+
+## Multi directional arrows
 
 There is the possibility to use multidirectional arrows.
 

packages/mermaid/src/docs/syntax/sequenceDiagram.md

@@ -83,6 +83,14 @@ sequenceDiagram
     Bob->>Alice: I agree
 ```
 
+#### Unfixable actor/participant creation/deletion error
+
+If an error of the following type occurs when creating or deleting an actor/participant:
+
+> The destroyed participant **participant-name** does not have an associated destroying message after its declaration. Please check the sequence diagram.
+
+And fixing diagram code does not get rid of this error and rendering of all other diagrams results in the same error, then you need to update the mermaid version to (v<MERMAID_RELEASE_VERSION>+).
+
 ### Grouping / Box
 
 The actor(s) can be grouped in vertical boxes. You can define a color (if not, it will be transparent) and/or a descriptive label using the following notation: