docs: Modify the blank line problem

Author: haozhihan

.github/ISSUE_TEMPLATE/bug-report.yml

@@ -7,55 +7,44 @@ body:
 - type: textarea
   attributes:
     label: Describe the bug
-    description: >
-      A clear and concise description of what the bug is. 
-      The bug may results in:
-      
+    description: |
+      A clear and concise description of what the bug is. The bug may results in:  
       - abnormal interruption of the program,
-      
       - systematic or randomized numerical error, or
-      
       - relatively low efficiency.
   validations:
     required: true
 
 - type: textarea
   attributes:
     label: Expected behavior
-    description: >
+    description: |
       A clear and concise description of what you expected to happen.
 
 - type: textarea
   attributes:
     label: To Reproduce
-    description: >
+    description: |
       Steps to reproduce the behavior:
-      
       1. [e.g. clone the source code from ...]
-      
       2. [e.g. configure CMake with options ...]
-      
       3. [e.g. build ABACUS with ...]
-      
       4. [e.g. run ABACUS with ...]
       
-      
       It is recommended to attach your calculation case here for the developers to reproduce the bug.
 
 - type: textarea
   attributes:
     label: Environment
-    description: >
+    description: |
       - OS: [e.g. Ubuntu 20.04]
-      
       - Compiler: [e.g. gcc 5.1.0]
-      
       - Dependencies: [e.g. Intel MKL, OpenBLAS]
 
 - type: textarea
   attributes:
     label: Additional Context
-    description: >
+    description: |
       Add any other context about the problem here.
 - type: markdown
   attributes:

.github/ISSUE_TEMPLATE/feature-request.yml

@@ -8,23 +8,23 @@ body:
 - type: textarea
   attributes:
     label: Background
-    description: >
+    description: |
       A clear and concise description of why this new feature is important.
   validations:
     required: true
 
 - type: textarea
   attributes:
     label: Describe the solution you'd like
-    description: >
+    description: |
       A clear and concise description of what you want to happen.
   validations:
     required: true
 
 - type: textarea
   attributes:
     label: Additional Context
-    description: >
+    description: |
       Add any other context or screenshots about the feature request here.
 
 - type: markdown

.github/ISSUE_TEMPLATE/help-wanted.yml

@@ -8,7 +8,7 @@ body:
 - type: textarea
   attributes:
     label: Details
-    description: >
+    description: |
       Want to use ABACUS for certain system? Facing problems when installing ABACUS? Don't know how to choose a good parameter? Feel free to reach us, and we'll do our best to help!
   validations:
     required: true

.github/ISSUE_TEMPLATE/software-enhancements.yml

@@ -8,19 +8,17 @@ body:
 - type: textarea
   attributes:
     label: Describe Current Status and Possible Solution
-    description: >
+    description: |
       A clear and concise description of why this enhancement is important. 
-
       Describing the current situation of ABACUS is preferred.
-      
       If you have some ideas about how to achieve it, please feel free to comment.
   validations:
     required: true
 
 - type: textarea
   attributes:
     label: Additional Context
-    description: >
+    description: |
       Add any other context or screenshots about the enhancement here.
 
 - type: markdown