chore: Fix spelling/grammar (#21260)

.github/ISSUE_TEMPLATE/config.yml

@@ -2,7 +2,7 @@ blank_issues_enabled: false
 contact_links:
   - name: "IMPORTANT: Check development branch changelog first!!"
     url: https://gist.github.com/Koenkk/bfd4c3d1725a2cccacc11d6ba51008ba
-    about: "Before submitting an issue, check if the issue hasn't already been solved in the development branch. Click 'Open' to see the release notes of the development branch. In case it is, you can read here how to switch to the development branch: https://www.zigbee2mqtt.io/advanced/more/switch-to-dev-branch.html"
+    about: "Before submitting an issue, check that the issue hasn't already been solved in the development branch. Click 'Open' to see the release notes of the development branch. In case it is, you can read here how to switch to the development branch: https://www.zigbee2mqtt.io/advanced/more/switch-to-dev-branch.html"
   - name: Questions/discussion
     url: https://github.com/Koenkk/zigbee2mqtt/discussions/new
     about: Ask questions, discuss about devices or show things you made

.github/ISSUE_TEMPLATE/feature_request.yaml

@@ -7,12 +7,12 @@ body:
     attributes:
       value: |
         **IMPORTANT:** Before submitting:
-        - Is your feature request related to the fronted? Then click [here](https://github.com/nurikk/zigbee2mqtt-frontend/issues/new?assignees=&labels=&template=feature_request.md&title=)
+        - Is your feature request related to the frontend? Then click [here](https://github.com/nurikk/zigbee2mqtt-frontend/issues/new?assignees=&labels=&template=feature_request.md&title=)
   - type: textarea
     id: textarea1
     attributes:
       label: Is your feature request related to a problem? Please describe
-      placeholder: A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
+      placeholder: A clear and concise description of what the problem is. Eg. I'm always frustrated when [...]
     validations:
       required: true
   - type: textarea

.github/ISSUE_TEMPLATE/new_device_support.yaml

@@ -36,7 +36,7 @@ body:
       required: true
   - type: textarea
     attributes:
-      label: External defintion
+      label: External definition
       description: See [Creating the external definition](https://www.zigbee2mqtt.io/advanced/support-new-devices/01_support_new_devices.html#_2-creating-the-external-definition)
       render: shell
     validations:

.github/ISSUE_TEMPLATE/problem_report.yaml

@@ -11,7 +11,7 @@ body:
         - Make sure the bug also occurs in the [dev branch](https://www.zigbee2mqtt.io/advanced/more/switch-to-dev-branch.html)
         - Make sure you are using the [latest firmware](https://www.zigbee2mqtt.io/guide/adapters/#recommended) on your adapter
         - The issue has not been [reported already](https://github.com/Koenkk/zigbee2mqtt/issues)
-        - Is your issue related to the fronted? Then click [here](https://github.com/nurikk/zigbee2mqtt-frontend/issues/new?assignees=&labels=bug%2Ctriage&template=bug_report.yaml&title=%5BBug%5D%3A+)
+        - Is your issue related to the frontend? Then click [here](https://github.com/nurikk/zigbee2mqtt-frontend/issues/new?assignees=&labels=bug%2Ctriage&template=bug_report.yaml&title=%5BBug%5D%3A+)
         - If you are using the Home Assistant addon and are still on 1.18.1, check the first point of [this](https://github.com/Koenkk/zigbee2mqtt/releases/tag/1.19.0)
   - type: textarea
     id: what_happend
@@ -30,7 +30,7 @@ body:
     id: reproduce
     attributes:
       label: How to reproduce it (minimal and precise)
-      placeholder: First do this, than this..
+      placeholder: First do this, then this..
     validations:
       required: false
   - type: input