[Material] Fix acrylic glass density and remove comments

src/Mod/Material/StandardMaterial/Acrylic-Glass.FCMat

@@ -4,32 +4,12 @@
 ; http://www.freecadweb.org/wiki/index.php?title=Material
 
 [FCMat]
-; General name, need to be the same as the file name
 Name = Acrylic Glass
-
-; Example of localized name. 2 letter codes as per ISO-639-1 https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes
-NamePL = Plexiglas
-
-; More elaborate description of this material card:
 Description = Poly(methyl methacrylate) (PMMA, acrylic, acrylic glass, trade names Plexiglas, Acrylite, Lucite, Perspex) a transparent thermoplastic often used in sheet form as a lightweight or shatter-resistant alternative to glass.
-
-; Example of localized description. 2 letter codes as per ISO-639-1 https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes
 DescriptionPL = Szkło akrylowe (szkło organiczne; inaczej pleksi, pleksiglas, metapleks) – przezroczyste tworzywo sztuczne, którego głównym składnikiem jest polimer – poli(metakrylan metylu) (PMMA).
-
+Father = of the material, i.e. for PLA is Thermoplast, for Steel is Metal Thermoplast
-; Father of the material, i.e. for PLA is Thermoplast, for Steel is Metal
-Father = Thermoplast
-
-; Product URL, recommended are wikipedia links
 ProductURL = https://en.wikipedia.org/wiki/Poly%28methyl_methacrylate%29
-
-; Young's Modulus (or E-Module) in [MPa], see http://en.wikipedia.org/wiki/Young%27s_modulus for the details
 YoungsModulus = 2 MPa
-
-; Poisson's ratio [unitless], see https://en.wikipedia.org/wiki/Poisson%27s_ratio for the details
 PoissonRatio = 0.38
-
+Density = 1190 kg/m^3
-; Density in [kg/m^3] https://en.wikipedia.org/wiki/Density
-Density = 1.19 kg/m^3
-
-; Yield strength in [MPa] https://en.wikipedia.org/wiki/Yield_%28engineering%29
 YieldStrength = 75 MPa