fixed typos in folder markdown files

Author: azlinszkysinergise

dem/dem.md

@@ -14,4 +14,5 @@ DEM (digital elevation model) is a 3D representation of the terrain's surface cr
   - [DEM sepia visualization](/dem/dem-sepia)
   - [DEM topographic visualization](/dem/dem-topographic)
   - [DEM contour lines](/dem/contour-lines)
-  - [DEM difference visualization](/dem/dem-difference)
+  - [DEM difference visualization](/dem/dem-difference)
+  - [DEM Central Europe](/dem/dem-central-europe)

sentinel-5p/sentinel-5p.md

@@ -41,6 +41,6 @@ Sentinel-5P provides atmospheric measurements, relating to air quality, climate
  - [Cloud Optical Thickness](/sentinel-5p/cloud-optical-thickness)
  - [Cloud Effective Radiometric Fraction](/sentinel-5p/cloud-radiometric-fraction)
 
- ### Additional Products
+ #### Additional Products
 
  - [Nitrogen Dioxide monthly mean](/sentinel-5p/no2_monthly_mean)